Project Feasibility Study for the Overseas Expansion of
Quality Energy Infrastructure in FY2018
(Reduction of RO Concentrate by applying Japanese Demineralization
Technology onto Wastewater Reclamation Process in the United States)
REPORT
March 2019
Ministry of Economy, Trade and Industry
Mizuho Information & Research Institute, Inc.
Zeolite Inc.
CONTENTS
Frequently Used Abbreviations and Acronyms .................................................................. 1
1.Policies and measures for wastewater treatment in the United States .................... 2
2.Grasp the state of treatment of RO membrane concentrate wastewater ................ 38
3.Concept of proposed system and confirmation of superiority ................................... 41
4.Business model and estimate of project cost ............................................................. 85
5.Finance and economic evaluation ............................................................................... 90
6.Governmental supports ............................................................................................... 92
7.Estimate of CO2 emissions reduction and environmental impacts ......................... 97
8.Risk analysis .............................................................................................................. 104
9.Project potential in the United States and the strategy ......................................... 105
10.Technological superiority of Japanese companies and estimate of profit for
Japanese participants ....................................................................................................... 108
11.Report Meeting ........................................................................................................ 111
1
Frequently Used Abbreviations and Acronyms1
ANSI American National Standards Institute
AOP advanced oxidation processes
ASR aquifer storage and recovery
BOD biochemical oxygen demand
CBOD carbonaceous biochemical oxygen demand
COD chemical oxygen demand
CWA Clean Water Act
DBP disinfection by-product
DO dissolved oxygen
DOC dissolved organic carbon
DPR direct potable reuse
EDC endocrine disrupting compounds
EPA U.S. Environmental Protection Agency
FDEP Florida Department of Environmental Protection
GAC granular activated carbon
HACCP Hazard Analysis and Critical Control Points
IPR indirect potable reuse
IRP integrated resources plan
LEED Leadership in Energy and Environmental Design
MBR membrane bioreactor
MCL maximum contaminant level
MF microfiltration
NDMA N-nitrosodimethylamine
NPDES National Pollutant Discharge Elimination System
PPCP pharmaceuticals and personal care product
PCR polymerase chain reaction
POC particulate organic carbon
RO reverse osmosis
SAT soil-aquifer treatment
SDWA Safe Drinking Water Act
SRT solids retention time
TDS total dissolved solids
TMDL total maximum daily load
TOC total organic carbon
TrO trace organic compounds
TSS total suspended solids
TWM total water management
UF ultrafiltration
USACE U.S. Army Corps of Engineers
1 EPA “2012 Guidelines for Water Reuse” (2012)
2
1.Policies and measures for wastewater treatment in the United States
1-1 Water reclamation for potable use
(1)Overview
On the reclamation of wastewater, US Environmental Protection Agency (EPA) defines three types
of water reclamation systems for potable reuse, De Facto Reuse, Direct Potable Reuse (DPR) and
Indirect Potable Reuse (IPR).2
Table 1 Water reclamation systems for potable use3
De Facto Reuse A situation where reuse of treated wastewater is practiced but is
not officially recognized (e.g., a drinking water supply intake
located downstream from a wastewater treatment plant [WWTP]
discharge point).
Direct Potable Reuse(DPR) The introduction of reclaimed water (with or without retention in
an engineered storage buffer) directly into a drinking water
treatment plant. This includes the treatment of reclaimed water at
an Advanced Wastewater Treatment Facility for direct
distribution.
Indirect Potable Reuse(IPR) Deliberative augmentation of a drinking water source (surface
water or groundwater aquifer) with treated reclaimed water,
which provides an environmental buffer prior to subsequent use.
2 EPA “2012 Guidelines for Water Reuse” (2012) 3 EPA “2012 Guidelines for Water Reuse” (2012)
3
Figure 1 Potable Water Reuse4
4 Texas Water Development Board “Direct Potable Reuse Resource Document” (2015)
4
For the water reclamation project in the countries and areas where dilution by De Facto Reuse is not
expected, various combinations of technologies have been developed. EPA says treatment train is to
be investigated considering situation of each site.
The degree of coordination and cooperation that can be achieved may vary from project to project
and from state to state. Therefore, states committed to achieving integrated water resources planning
goals may choose to adopt laws that consolidate regulatory programs to the extent possible or
improve the coordination and cooperation among programs of different state agencies for the
purpose of facilitating this planning framework.5
Especially in the States of Arizona, California, Florida and Texas, there have been various initiatives
towards water reclamation; therefore, EPA has developed the guideline for wastewater reuse, including
potable reuse6.
The guideline also mentions that local governments or water related departments should make much
clearer investigation of technologies, development of laws with responsibility towards implementing
DPR or IPR of wastewater reclamation treatment. Now the states of California and Texas have been
taking initiatives to organize and systematize the technology information towards future state laws and
regulations.
Potable water standard in the United States is based on Safe Drinking Water Act (SDWA), and
wastewater standard on Clean Water Act (CWA). SDWA is the federal law managed by US EPA. Both
public and private water systems have been obliged to supply water with compliance of water standard
set by EPA and local governments. CWA is also the federal law regulating the wastewater emissions
and its standards. It has set up the limitation by National Pollutant Discharge Elimination System, uder
which pollutant discharge is allowed by expanding from each emission source to the area. The
standards are regulated more strictly in the area where it is hard to restore or sustain, which is decided
by each state in depending on the purpose of water usage. On water reclamation, US EPA supports
States and local governments to make their own regulations and guideline, and makes out guidelines
for water reuse. States and local governments have responsibilities for water reuse and water quality
standards, hence there is no regulations under the federal government.
Situation in the State of California has been affecting on the water reclamation projects including
potable use in the other states of United States. Therefore, it is slso important for the F/S to focus on
the laws and technology information under the California State Water Resources Control Board
(SWRCB).
5 EPA “2012 Guidelines for Water Reuse” (2012) 6 EPA “2012 Guidelines for Water Reuse” (2012)
5
History of IPR begins by the projects of the SWRCB in the Orange County, San Francisco, in which
penetration of recycled water and injection of surface water into groundwater in 1965 and 1976
respectively, for the purpose of avoiding seawater damage into groundwater. From the introduction of
law on groundwater recharge using recycled water in 1978 by the California Department of Public
Health (CDPH), revision of the law has been developed for the purpose of recharging reclaimed water
into aquifer.
SWRCB has clarified that definition of IPR includes that there is environmental buffer to keep
recycled water for equal or more than two months as groundwater or environmental water7.
Among the operating IPR projects, the combination of secondary and tertiary treatment followed by
RO membrane treatment as advanced treatment can be found out more than oznone treatment.
And, there are many IPR projects in which potable water is supplied directly or through chrorination
after the storage in the aquifer (soil-aquifer treatment). The case of Namibia is DPR without soil-
aquifer treatment.
Figure 2 Examples of potable reuse schemes8
7 SWRCB“A Proposed Framework For Regulating Direct Potable Reuse In California” (2018) 8 WHO “Potable Reuse / Guidance for Producing Safe Drinking-Water” (2017)により作成
RO membrane
Ozone
Soil-aquifer treatment
6
Table 2 Pioneering potable reuse schemes (DPRand IPR)9
Type Site Situation
IPR Montebello Forebay,
United States of
America
Potable reuse was first implemented in the 1960s using surface
spreading followed by SAT, where wastewater after secondary
treatment, chlorination and media filtration is infiltrated through
the vadose zone into the aquifer at the Rio Hondo and San Gabriel
Coast Spreading Grounds. The recharged groundwater blended
with native groundwater is subsequently recovered, disinfected
and fed into the drinking-water distribution system.
IPR Orange County,
United States of
America
Potable reuse was introduced with development of Water Factory
21 in 1976. The scheme included injection of treated wastewater
into a coastal aquifer. Water Factory 21 was replaced by the
Groundwater Replenishment System in 2007. Following
treatment by conventional biological wastewater processes, MF,
RO, AOP (UV/H2O2), stabilization and final chlorination,
wastewater is injected into the coastal aquifer to provide a
seawater intrusion barrier and percolated from several lakes into
groundwater used as a source of drinking-water that is often not
chlorinated after withdrawal.
DPR Windhoek, Namibia The first DPR scheme was introduced in the 1960s. The current
scheme combines biological treatment, ozonation, dissolved air
flotation, media filtration, activated carbon adsorption and
ultrafiltration (UF) of wastewater, with the product water blended
with drinking-water produced from surface water/groundwater
and fed into the drinking-water distribution system.
(2)Methods of water treatment
The followings show the important water reclamation ways.
Table 3 Important water reclamation ways10
Primary
treatment
Primary treatment is essentially a physical treatment process which removes
suspended solids.
It removes some organic nitrogen, phosphorus and heavy metals but only
9 WHO “Potable Reuse / Guidance for Producing Safe Drinking-Water” (2017) 10 WHO “Potable Reuse / Guidance for Producing Safe Drinking-Water” (2017) etc.
7
provides limited removal of microbial pathogens.
Secondary
treatment
Secondary treatment involves biological digestion and is commonly based on
some form of ASP or trickling filters.
It removes organic materials by digestion and should reduce biochemical
oxygen demand and suspended solids by 85% or more
Particle bound chemicals are removed and concentrations of microbial
pathogens are reduced.
Nitrification and denitrification processes, in particular, can greatly improve
water quality for downstream processes such as advanced oxidation and
chlorination by removing ammonia and nitrate, respectively.
Tertiary
treatment
Tertiary treatment is an expensive component of wastewater treatment,
especially as it involves the cultivation of fastidious bacteria and the sequential
use of oxic, then anoxic conditions, usually requiring multiple tanks and
pumping systems.
SAT (soil-
aquifer
treatment)
From a technical point of view, perhaps the most basic and robust potable reuse
treatment is groundwater infiltration, which is also known as SAT. Soil-aquifer
treatment is a low technology process where treated wastewater percolates from
spreading basins through soil which provides nutrient, microbial and chemical
attenuation.
Soil-aquifer treatment requires availability of unconfined aquifers, vadose zones
with no constricting layers and soil that allows for infiltration while being fine
enough to provide filtration. Subsequent aquifer storage also results in reduction
of microbial pathogens and some chemical contaminants.
Oxidative
processes
Many potable reuse treatment schemes utilize an oxidative process for
attenuation of organic contaminants.
The most common oxidative processes, ozonation and AOP, can be extremely
effective but by-product formation must be carefully monitored and controlled.
Operational and energy costs are high. Advanced oxidation processes enhance
degradation of chemical contaminants through increased production of
hydroxyl radicals from hydrogen peroxide (H2O2) and UV light or ozone and
UV light.
Advanced oxidation is effective against a wider range of organic chemicals and
at higher reaction rates than standard oxidation processes. Using processes such
as biological active carbon (BAC) following oxidative processes can be very
effective for reducing many organic transformation compounds produced by the
oxidation step, although some substances such as bromate are generally not
8
effectively removed.
Activated
carbon
adsorption
Adsorptive activated carbon can remove the vast majority of organic
contaminants. However, breakthrough from the activated carbon can occur as a
function of molecular structure or contaminants, water quality, the type of
activated carbon, and the operational parameters employed.
The use of activated carbon can be relatively expensive and will require periodic
replacement or reactivation.
Activated carbon also can serve as a support structure for the growth and
retention of biological organisms resulting in formation of BAC which may be
operated as a stand-alone process or preceding absorptive granular activated
carbon (GAC).
Low
pressure
membrane
filtration
Low pressure membrane filtration includes MF and UF with pore sizes ranging
from 0.1–0.2 microns for MF to 0.01–0.05 microns or less for UF.
Membrane filtration is being used with increasing frequency in drinking-water
and wastewater reuse schemes as effective barriers for pathogenic protozoa and
to a lesser extent the smaller viral pathogens.
In potable reuse schemes membrane filtration can be used to provide
consistently low turbidity water that reduces fouling of subsequent processes
such as NF and RO.
High
pressure
membrane
filtration
High pressure desalting membranes such as RO and NF are extremely effective
physical barriers for all pathogens and most organic contaminants.
Most RO membranes can remove upwards of 99% of salinity from water and
hence are expected to provide an even greater removal of microbial
contaminants.
Nanofiltration is not as effective in removing salinity but will remove substantial
amounts of higher valent ions like calcium, magnesium and sulfate.
Figure 3 Membrane filtration pore sizes11
11 WHO “Potable Reuse / Guidance for Producing Safe Drinking-Water” (2017)
9
(3)Processes after treatment
The following are the important process after the water treatment itself. Especially, it is the most
important to investigate the level of LRV (Log Reduction Value) for each pathogen.
Table 4 Important process after the water treatment
Environmental buffer12 A key element of IPR is an environmental buffer. The
environmental buffer, either an aquifer or a surface water
reservoir, provides a number of potential benefits, including
contaminant attenuation, dilution and blending, and time to
detect and respond to failures before final treatment and
distribution. Environmental buffers also provide storage
capacity to hold water during periods when production exceeds
demand.
Engineered storage buffer13 An ESB is a storage basin or system that provides sufficient
time, termed the failure and response time, to interrogate and
respond to any faults, including exceedances of critical limits in
operational monitoring of the treatment train. Storage times in
ESBs are likely to be of the order of hours to days.
LRV LRV (Log Reduction Value) is a measure of the ability of a
treatment processes to remove pathogenic microorganisms.
LRV is determined by taking the logarithm of the ratio of
pathogen concentration in the influent and effluent water of a
treatment process.
Removal Survival LRV
――――――――――――――――――
90% 10% 1
99% 1% 2
99.9% 0.1% 3
99.99% 0.01% 4
99.999% 0.001% 5
Treatment of LRV 1 (removal by 90%) followed by treatment of
LRV 2 (removal by 99%) means LRV 3 (removal by 99.9%).
12 WHO “Potable Reuse / Guidance for Producing Safe Drinking-Water” (2017) 13 WHO “Potable Reuse / Guidance for Producing Safe Drinking-Water” (2017)
10
(4)Public acceptance14
Nevada Initiative includes to develop indirect potable reuse (IPR) as a viable water management
strategy for the community within 5 years, and has been conducting the followings:
Project development
Community outreach
Nevada regulations
Pilot testing technologies
Demonstration project
Hydrogeologic investigations
Funding
In the processes shown above, experts are helping guide and critique their regional work organized by
National Water Research Institute.
Table 5 Public engagement in the City of Reno
Phase 1 Agency meetings
Regional staff Krishna Pagilla, PhDs
3 PhD candidates
Access to university system resources
Boards and commissions
Authorizing public
Phase 2 Pilot testings Optimization of Ozone-BAC
9 month field pilot testing
Xylem, Stantec, American Water and
Washoe County
Demonstration project UNR and NWII
Xylem provides treatment equipments
14 Rick Warner (Washoe County, NWII Board Chair, WEF President) “Water Reuse in the United
States / A New Era”, Water Environment Federation (2017)
11
1-2 Situation of IPR/DPR in the United States
(1)Overview
The figure below shows IPR and DPR projects in the United States. There have been many RO-based
projects in the western part of United States including the State of California, which was one of the
pioneering states to promote IPR. The IPR projects in California were implemented for the purpose of
supplying potable water through both emitting treated water into reseavoir and soil-aquifer treatment
in the groundwater. The State Water Resources Control Board has investigated on the adequate
regulations and controls to conduct DPR, followed by the result that DPR is feasible in the state. Based
on that, the State of California has started to investigate regulations towards DPR project.
In contrast Ozone-based treatment project is hardly found in the western area, then we can understand
that RO-based treatment is valid for IPR.
In the State of Nevada there has been no commercial project of IPR or DPR based on membrane
technology. Currently demonstrarion project utilizing Ozone + BAC treatment is carried out in the
South Truckee Meadows Water Reclamation Facility.
Figure 4 IPR/DPR projects and RO applications in the United States15
15 EPA “2017 Potable Reuse Compendium” (2017)
RO applied
12
(2)Water reuse in the five states
In particular focus is water reuse in the five states of Nevada, California, Texas, Florida, and Arizona
("five states").
As shown in the figure below, the States of California and Florida are estimated to dominate the market
of water treatment of United States by 79% (amount of reclaimed water).
In the State of Texas which is expected to have third largest market of water reclamation, the treatment
has been conducted on the premise that the treated water is deluted, therefore, the requirement level
of treatment against pasogens is not high (“Texas” approach).
Both the States of Nevada and Arizona are investigating guidelines and regulations for water
reclamation taking the framework of California into consideration as the model (“California”
approach). Urban population and functions tend to move from California to Phenix (Arizona) and Las
Vegas (Nevada), which means the situation of California tends to spread to those two states. Those are
the reason why the focus of the F/S are on the followers of California (Arizona and Nevada), in
addition to the three states which will have top three market of water reclamation (California, Florida
and Texas).
Figure 5 Outlook of water reclamation capacity in the five states of the United States (m3/day)16
16 BlueField Research
13
Figure 6 Five states focused in water reuse
① Levels of LRV
Comparing the pathogen concentrations typically measured in treated effluent to conventional
surface water sources forms the basis for high-level pathogen removal requirements. Although there
are various approaches taken by each state for log reduction values (LRV), virus, Cryptosporidium,
and Giardia are ubiquitous in potable water reuse regulatory/guidance documents. Bacteria are also
included in many of these documents, however the advanced treatment processes necessary to
achieve LRVs for other pathogens are capable of also addressing the bacteria LRV. Attenuation of
pathogens through environmental buffers is not well characterized and IPR projects may have
limited travel time and/or mixing, complicating the distinction between IPR and DPR. Table below
compares the regulatory approach for the removal of pathogen and other contaminant for potable
water reuse applications.
The requirement levels of pathogens removal would be almost the same between Califoania and
Nevada. However, the State of Nevada has not experienced conducting IPR nor DPR to date, and it
depends on groundwater as potable water much more than California, especially the northern part of
the state. Therefore, the investigation to introduce IPR in the State of Nevada is supposed to be made
carefully.
California
Nevada
Arizona
Texas
Florida
14
Table 6 Pathogens Log Removal and Contaminates Guidelines or Regulatory Requirements for
Potable Water Reuse
State Virus
[log removal]
Giardia
[log removal]
Cryptosporidium
[log removal]
Bacteria
[log removal] Contaminants
Nevada 12 10 10 not specified MCLs, Secondary
MCLs
Arizona (“California”
approach) 12 10 10 9
MCLs, Secondary
MCLs, CECs
Arizona (“Texas”
approach) ≥8 ≥6 ≥5.5 not specified MCLs
Texas ≥8 ≥6 ≥5.5 not specified MCLs
Florida not specified not specified not specified not specified MCLs, Secondary
MCLs, TOC, TOX
California (Groundwater
spreading and injection) 12 10 10 9(4)
MCLs, Secondary
MCLs, CECs
California (Surface
Water Augmentation) 12 10 10 9(4)
MCLs, Secondary
MCLs, CECs
Note: MCLs: Maximum Contaminant Levels
CECs: Contaminants of Emerging Concern
TOC: Total Organic Carbon
TOX: Total Organic Halide
② Treatment methods for potable reuse
There are two advanced treatment approaches commonly considered for potable water reuse: RO-
based and granular activated carbon (GAC)-based. A combination of various advanced treatment
processes are utilized in both of these approaches to address the advanced removal requirements
outlined by individual states to ensure the safety of potable water reuse water.
a. RO-based treatment
RO-based treatment has traditionally been the most commonly implemented potable water reuse
approach and is often referred to as Full Advanced Treatment (FAT). This scheme provides robust
barriers, primarily in RO and ultraviolet advanced oxidation process (UV/AOP), for the removal and
15
destruction of organics, pathogens, and CECs. Fewer processes are utilized in this approach compared
to the GAC-based treatment approach; however, the equipment is more expensive from both a capital
and lifecycle cost perspective and even more so at inland locations where the RO concentrate disposal
requires costly handling processes (i.e., crystallization or deep well injection) as opposed to coastal
locations where ocean disposal is feasible.
The Colorado River Municipal Water District project in Big Spring, Texas is the quintessential
example of an RO-based potable water reuse facility. The combination of membrane and advanced
oxidation treatment processes provide approximately 15 percent of the source water to a conventional
drinking water treatment facility. This approach, shown in Figure 1 below, is also utilized for IPR
projects in California and elsewhere.
Figure 7 Example of FAT Treatment Train Using Reverse Osmosis (DPR in Big Spring, Texas
includes blending and additional treatment at the downstream conventional WTP)
b. GAC-based treatment
The GAC-based treatment process is a multiple barrier scheme with a variety of treatment and removal
mechanisms including oxidation, physical removal, and adsorption. This GAC-based treatment
approach, shown in Figure 2 below, is capable of achieving target water quality parameters for
pathogens and CECs; however, it does not remove total dissolved solids (TDS).
Figure 8 Example Potable Water Reuse Treatment Train Using Ozone and Biofiltration
16
③ Five states
The followings presenting a summary of water reuse regulatory considerations and implementation in
the United States. Of particular focus is water reuse in the five states of Nevada, California, Texas,
Florida, and Arizona ("five states").
a. California
California has been implementing IPR projects since the early 1970s based on draft regulations. IPR
regulations for groundwater recharge were finalized in 2014. Three different types of IPR projects
have been approved in California. The first involves spreading (percolation) of a "tertiary" reclaimed
water, with long running projects using this approach within Southern California. The second is the
injection of a purified reclaimed water directly into the groundwater aquifer. A primary example is the
100 million gallons per day (mgd) Orange County Water District Groundwater Replenishment System
(GWRS). The augmentation of surface water bodies (such as a reservoir) with purified reclaimed water
is new to California, with the City of San Diego’s project beginning construction in 2019. All three of
these approaches to potable water are considered to be IPR because they incorporate an environmental
buffer (e.g., groundwater aquifer or surface water reservoir). Potable water reuse projects that do not
have an environmental buffer, or projects that have a very small environmental buffer, are classified
as DPR projects.
California has seven actively producing potable water reuse projects, with a total capacity of 206 mgd.
The California health criteria for these types of projects are summarized. In 2010, Senate Bill (SB)
918 directed the State Water Resource Control Board (SWRCB) to investigate the feasibility of
developing uniform water recycling criteria for DPR, convene an Expert Panel to study the technical
and scientific issues, and provide a final report to the California State Legislature by December 31,
2016. In 2013, SB 322 further required that the SWRCB convene an Advisory Group comprised of
utility stakeholders to advise the SWRCB and its Expert Panel on the development of the feasibility
report. SB 322 also amended the scope of the Expert Panel to include identification of research gaps
that should be filled to support the development of uniform water recycling criteria for DPR. Based
on the recommendations of the Expert Panel, the SWRCB DDW released its final report on the
feasibility of DPR in California in December 2016. The report is titled "The Feasibility of Developing
Uniform Water Recycling Criteria for Direct Potable Reuse.” The SWRCB found that developing
regulations for DPR projects was feasible and that a common framework across the various types of
DPR will help avoid discontinuities in the risk assessment and management approach. The SWRCB
noted that further research demonstrating reliability is necessary in order to finalize regulatory criteria
17
for DPR in California.
The report provides recommendations on topics that must be addressed in order to successfully adopt
uniform water quality criteria for DPR that are protective of public health. The SWRCB developed
Draft criteria to guide future DPR regulations in April 2018, in parallel with conducting necessary
research.
In 2017, the California legislature passed State Assembly Bill (AB) 574 in response to the feasibility
report. AB-574 defined a roadmap for DPR in California (AB-574, 2017). The bill defined the two
forms of DPR as “raw water augmentation” and “treated drinking water augmentation.” In addition,
the bill requires the SWRCB to adopt uniform water recycling criteria for “raw water augmentation”
by December 31, 2023. The bill requires the state board to establish and administer an expert review
panel to review the criteria.
b. Texas
As a state, Texas has implemented numerous water reuse projects. Texas has a successful track record
of two operational DPR facilities (Big Spring and Wichita Falls) and a third facility in the design phase
(El Paso Water). The Big Spring DPR system is a permanent installation that has been operational
since 2013, whereas Wichita Falls modified the temporary DPR system in 2015 (commissioned in
2014) for surface water augmentation (IPR), as planned. El Paso Water is now moving ahead with the
design of its own DPR project, which will be the first "treated water augmentation" project in the
United States, in which the purified water will be conveyed directly to the potable water distribution
system.
The Big Spring and Wichita Falls projects were approved by Texas regulators on a case-by-case basis
in accordance with the innovative/alternative treatment clause in 30 TAC (Texas Administrative Code)
290 regulatory document that allows “any treatment process that does not have specific design
requirements” listed in that chapter to still be permitted. The Texas Water Development Board
(TWDB) commissioned a technical team to develop a resource document to support water utilities,
consultants, and others who are considering future DPR projects in Texas. The "Direct Potable Reuse
Resource Document" (TWDB, 2015) provides information on issues utilities need to address for DPR,
how to address these issues, and a timeline for consulting with regulators about a project and site-
specific considerations.
DPR projects in Texas must be designed to meet all existing requirements for drinking water standards.
Additionally, monitoring of unregulated constituents (i.e., CECs) is encouraged by the Texas
Commission on Environmental Quality (TCEQ), but not mandated. TCEQ's approach is to understand
the pathogen concentrations in the source water to the advanced water treatment facility (AWTF), then
require a multiple-barrier treatment system to provide the necessary pathogen reduction to meet
18
acceptable risk standards.
TCEQ adopted its pathogen risk standards for potable water reuse in general accordance with the
approach taken in existing federal drinking water regulations, which is to achieve a goal of less than
1 in 10,000 annual risk of infection from each pathogen group. Similar to California's and the NWRI's
subsequently published approaches, the specific pathogen concentration targets are based on the
literature underpinning current federal drinking water regulations, which defines the concentration
target for enteric virus, Giardia, and Cryptosporidium as 2.2 x 10-7 MPN/L (Regli et al, 1991), 6.8x10-
6 cysts/L (Regli et al, 1991), and 3.0 x 10-5 oocysts/L (Haas et al, 1999), respectively.
LRV targets for each project are determined by calculating the difference between the target
concentrations listed above and actual values measured in the treated effluent, which is considered the
"source water" for the potable water reuse project. In addition, the TCEQ has defined minimum
"benchmark" LRV targets of 8-log virus, 6-log Giardia, and 5.5-log Cryptosporidium.
In all cases, LRV credits can only be achieved in accordance with drinking water guidance, such as
the EPA's Ultraviolet Disinfection Guidance Manual for UV systems, the EPA's Membrane Filtration
Guidance Manual for membrane systems, the Long Term 2 Enhanced Surface Water Treatment Rule
(LT2) Toolbox Guidance Manual, and others.
In effect, the TCEQ has developed a system of source water characterization analogous to the existing
"binning" process for Cryptosporidium under the LT2. The TCEQ's approach, however, also
acknowledges the substantially more impaired water quality of typical wastewater effluent compared
to conventional surface water sources by extending the source water characterization to all three
pathogen groups and imposing minimum treatment requirements that go beyond that required for
conventional source waters.
c. Florida
The Florida Department of Environmental Protection (FDEP) has clear regulations on IPR (Chapter
62-610 Reuse of Reclaimed Water and Land Application and drinking water regulations Chapter 62-
550 Drinking Water Standards, Monitoring, and Reporting). A guidance document is currently being
drafted to support the development of future DPR regulations in Florida (expected completion in early
2019). In additional to standard primary and secondary MCLs, the FDEP requires IPR projects to
attain a total organic carbon requirement of 3 milligrams per liter (mg/L) (or less) and to attain a total
organic halides (TOX) result of <0.2 mg/L.
d. Arizona
19
Non-potable water reuse is ubiquitous in Arizona, particularly for irrigation (agriculture or
landscaping) and has been successfully utilized for industrial applications. The first reclaimed water
regulations were promulgated in the state in 1972. IPR is allowed by use of groundwater recharge or
surface water augmentation with water that meets SDWA requirements. The City of Scottsdale has
been implementing a non-potable and IPR system since 1998. DPR had been specifically prohibited
until the DPR prohibition was repealed in 2017.
A guidance framework document was published in 2018 to lay the foundation for the development of
future DPR regulations in Arizona. Final DPR requirements are expected to be added to the Arizona
Administrative Code in the near future (possibly 2019). The approach for regulating potable water
reuse in Arizona is expected to allow for either the risk-based approach similar to Texas to establish
lower LRV requirements, or the “California” approach for fast-tracked projects that will follow the
12/10/10 approach for pathogen log reduction values (note that RO is not anticipated to be a required
technology in Arizona due to the recognition of RO concentrate disposal challenges).
e. Nevada
Adopted Regulation R101-16 describes reclaimed water in Nevada. Approved uses include non-
potable water reuse (landscape and food crop irrigation) and IPR (groundwater recharge via injection
or surface spreading) with reuse categories A through E defined by level of treatment and approved
uses.
Water in Nevada intended for IPR must meet reuse category A+ (NAC 445A.2761.1). A 12-log LRV
for virus is required from raw sewage to the point of extraction from the aquifer. 10-log LRV for
Cryptosporidium and Giardia is required from raw sewage to the zone of saturation. Nevada
regulations share many similar requirements to the California IPR regulations. Specific to Washoe
County, non-potable reclaimed water service is described in Washoe County Ordinance No. 1535.
20
Figure 9 Location of Washoe County and maincities of the northern part of Nevada
Reno is the capital of Nevada and is located in the northwestern part of the state in Washoe County.
The WaterStart program was initiated to spur economic development in Nevada through collaboration
and investment in water projects and technologies. Although the Reno area does not necessarily face
the magnitude of water scarcity challenges as other areas in the state of Nevada. Most water used in
this area is derived from the Sierra Nevada mountain snowpack. This source is susceptible to drought
(low snowfall) and therefore non-potable water reuse for irrigation has been implemented to preserve
this surface water supply.
Moving from non-potable water reuse to potable water reuse has been spurred by the development of
IPR regulations. Due to Reno and northern Nevada’s inland location, RO-based treatment presents
substantial challenges without innovative methods for higher recovery systems and innovate
concentrate management.
The Truckee Meadows Water Authority (TMWA) is the primary water provider for the approximately
400,000 residents in the cities of Reno and Sparks and greater Washoe County. The primary drinking
water sources are the Truckee River and groundwater. The TMWA provides approximately 11,000
acre-feet of water annually (3,000 acre-feet from the Truckee River and 8,000 acre-feet from Honey
Lake).
Washoe County
Clark County
Washoe County
Reno
Nevada
21
Figure 10 Truckee River (left) and Honey Lake (right)
Water reclamation facilities in Washoe County are as follows:
Table 7 Water reclamation facilities in Washoe County
Name Capacity Owner Operation
STMWRF (South Truckee Meadows
Water Reclamation Facility)
1.8 MGD
(3.0 MGD)
Washoe County In Operation
RSWRF (Reno/Stead Water
Reclamation Facility)
1.1 MGD
(1.5 MGD)
Washoe County -
Lemon Valley (CDP)
〃
TMWRF (Truckee Meadows Water
Reclamation Facility)
31.5 MGD
(40 MGD)
Washoe County – Reno
and Sparks
〃
Cold Springs Wastewater Treatment
Facility
0.13 MGD
(0.35 MGD)
Washoe County 〃
Verdi Meadows Wastewater
Treatment Plant
0.023 MGD
(0.028 MGD)
Verdi Meadows Utility
Company
Plan
Boomtown Wastewater Facility 0.14 MGD
(0.18 MGD)
Washoe County –Verdi
(CDP)
〃
Gold Ranch 0.010 MGD
(0.010 MGD)
Washoe County – Gold
Ranch (CDP)
〃
Lemmon Valley Wastewater
Treatment Plant
0.22 MGD
(0.3 MGD)
Washoe County 〃
22
STMWRF (South Truckee Meadows Water Reclamation Facility)
Washoe County Community Services Department (CSD) provides stormwater management,
wastewater treatment (average of 5 mgd), and reclaimed water. The CSD serves approximately 16,000
customers, which represents a small percentage of the overall Washoe County population. The CSD
operates three wastewater treatment facilities however only the South Truckee Meadows Water
Reclamation Facility (STMWRF) produces reclaimed water for non-potable irrigation. Approximately
800 million gallons of Class A reclaimed water are produced from this 4.1 mgd facility every year
(since 2000). STMWRF is an activated sludge plant followed by clarification, sand filtration, and
chlorine contact basins for disinfection. During irrigation season, reclaimed water is conveyed to the
distribution system. During the winter, treated effluent is stored in an open-air reservoir.
RSWRF (Reno/Stead Water Reclamation Facility)
The City of Reno and the City of Sparks are the primary wastewater treatment providers in Washoe
County. The City of Reno operates the Reno/Stead Water Reclamation Facility (RSWRF). The
RSWRF effluent (average of 1.5 mgd) is utilized for non-potable irrigation as well as discharge to
Swan Lake, a wildlife conservation area. Like STMWRF, RSWRF is an activated sludge plant
followed by tertiary filtration and disinfection.
TMWRF (Truckee Meadows Water Reclamation Facility)
The City of Sparks operates the Truckee Meadows Water Reclamation Facility (TMWRF), jointly
owned by the Cities of Sparks and Reno. The TMWRF has a treatment capacity of 39.8 mgd. The
TMWRF is a tertiary treatment plant with unit processes that include primary clarification, secondary
treatment (activated sludge process with EBPR), fixed-film nitrification (nitrification towers) and
denitrification (fluidized bed reactors) processes, granular media filters, sodium hypochlorite
disinfection, and sodium bisulfite dechlorination. The final effluent is discharged year-round to the
Truckee River via Steamboat Creek.
Carson City Water Resource Recovery Facility
Other utilities in Northern Nevada include the City of Carson City and the City of Winnemucca. The
Carson City Water Resource Recovery Facility is a 6.9 mgd tertiary facility comprised of primary
treatment followed by activated sludge (bioreactors, secondary clarifiers), tertiary filters, and chlorine
contact basins for disinfection. Treated effluent is reused at local golf courses and parks during the
23
irrigation season, and stored in a reservoir during the winter.
Winnemucca Wastewater Treatment Facility
The Winnemucca Wastewater Treatment Facility is a 3.5 mgd plant comprised of preliminary and
secondary treatment (bioreactor and clarifiers) for denitrification. According to its permit, effluent is
used for agricultural crops, not for human consumption.
24
Figure 11 Water reclamation facilities in Washoe County17
17 Northern Nevada Water Planning Commission
25
(3)Reference projects in the States of Nevada and California
The following four projects are to be references for the F/S.
Table 8 Reference projects
1. Orange County – California The first project in which treated water is
injected into groundwater (in the beginning, as
the barrier against seawater intrusion)
The world largest IPR project
2. Chino – California The latest IPR project (completed in May 2017)
RO membrane is used
High recovery ratio (over 94%)
3. Henderson – Nevada “South Nevada” model
Water resource is mainly surface water
RO membrane is not used
4. Reno – Nevada “North Nevada” model
Water resource is mainly groundwater
Demonstration project of the Ozone + BAC
treatment is implemented
Figure 12 Location of reference projects
Chino - California
Orange County - California
Henderson - Nevada
Reno - Nevada
26
Those reference projects are identified and selected from the viewpoints shown below:
Table 9 Features of the reference projects
Project Groundwater
injection
RO-based High-
recovery
RO
IPR
1. Orange County – California ○ ○ × (coast) ○ (largest)
2. Chino – California ○ ○ ○ (inland) ○ (latest)
3. Henderson – Nevada × × - ×
4. Reno – Nevada ○ × (O3) - ○ (demo)
① Orange County – California
Orange County is located in the southern part of Los Angeles and north of San Diego. Partly because
of that location between two large urban areas, the population is more than 3.2 million in 2018 and
increasing by 0.7% The populations of Los Angeles and San Diego are 10.28 million and 3.34,
respectively, and the growth rates are 0.5% and 0.8% annually, respectively, in 2018.
Figure 13 Location of Orange County
Colorado River
27
Water Factory 21 was established in Orange County, California in 1976 as the first project utilizing
direct injection of recycled wastewater as a seawater intrusion barrier. The Orange County Water
District (OCWD) obtains water from the Santa Ana River, the Colorado River, the State Water Project
(Delta conveyance), local precipitation, and recycled water from the Orange County Sanitation District
(OCSD). Starting in 2004 and completed in 2008, the OCWD upgraded their recharge system by
superseding Water Factory 21 with the unveiling of a 70 MGD Groundwater Replenishment System
(GWRS) – the world’s largest advanced water treatment system for potable reuse.
During construction of the GWRS, the Interim Water Factory operated from 2004-2006 and produced
5 MGD of reclaimed water utilizing MF, RO, and UV-AOP with hydrogen peroxide. This water was
blended with 8 MGD imported water before being used for groundwater replenishment and seawater
intrusion prevention. At the GWRS, influent water flows from the OCSD Plant 1 to the GWRS. After
treatment, the GWRS pipelines initially distributed 35 MGD of purified reclaimed water from the
OCWD’s facility located in Fountain Valley to groundwater recharge basins (Kraemer, Miller, and
Miraloma) located in Anaheim. The purified water flows year-round through a 13-mile long pipeline
before reaching and percolating through recharge basins that provide up to 75% of the drinking water
supplied to the northern and central parts of the OCWD. The other 35 MGD was pumped into the
Talbert Gap seawater intrusion barrier injection wells. The plant completed an expansion to 100 MGD
in 2015. The expansion included the addition of two 7.5 million gallon equalization tanks to help
increase production due to limited availability of wastewater from OCSD Plant 1. The facility is
planning a future expansion to 130 MGD and is evaluating alternatives for providing additional
wastewater flows for both the current and expanded facility. At 70 MGD, the GWRS served
approximately 600,000 people. With the completed expansion, the GWRS will produce enough water
to sustain a population of 850,000 people.
The GWRS treatment process utilizes MF, RO, UV-AOP with hydrogen peroxide as part of the
advanced purification process follow by decarbonation and lime addition. The MF process has a 90%
recovery rate at the GWRS; backwash from the process is sent to OCSD Plant 1 for treatment and
returned to GWRS. Each MF cell experiences backwashing every 22 minutes to prevent high-pressure
buildup. Additionally, each microfiltration cell receives a full chemical cleaning every 21 days. The
RO process has an 85% recovery rate and the resulting brine is distributed to the OCSD ocean outfall.
MF and RO are followed by UV trains each consisting of six low pressure, high output UV reactors
in series, each with 72 lamps. Following UV disinfection, the water is stabilized to pH levels between
8.5 and 9 by partial degasification and lime addition.
Table 10 Orange County Groundwater Replenishment System (GWRS)
Capacity 270 thousand m3/day (71 MGD)
Treatment train raw water
28
MF
UF
UV + decarbonator
Injection to groundwater
Figure 14 Process flow diagram18
In the inland area of North Nevada water demand depends on groundwater much more than Southe
Nevada or California, then it is required to minimize the risk against polluting the groundwater
resources. Therefore, it is necessary for the F/S project to apply technologies much more than advances
than in Orange County.
18 EPA
29
② Chino - California19
Coastal utilities typically discharge their treated wastewater to a receiving stream in close proximity
to the ocean or directly to an ocean outfall. Leveraging the permitting and capital costs associated with
these discharges of other waste flows is an economical approach to implementing potable water reuse
for these utilities.
Multiple utilities in Southern California have contributed to a large concentrate interceptor pipeline as
a regional approach to cost effectively discharge the concentrate from several treatment facilities in
the area that utilize RO for either brackish groundwater, desalination, or as part of an IPR treatment
process. Even in this scenario, utilities have an incentive to minimize their concentrate flows to
manage the cost of purchasing/utilizing interceptor or outfall capacity.
An example of this concept is the Chino II Concentrate Reduction Facility Project.
Figure 15 Location of Chino
This groundwater treatment system relies on a combination of RO and ion exchange to address TDS,
nitrates, and volatile organic compounds in the groundwater sources. Brine is discharged to the Santa
Ana Regional Interceptor pipeline which ultimately discharges to an ocean outfall. The total facility
raw water flow rate is 20.5 mgd with both RO and ion exchange treatment. All water treated at this
facility is supplied from the more than 800 groundwater wells in the system.
Expansion of the overall treatment process in Chino resulted in the total brine flow projected to exceed
the allotted capacity in the brine interceptor. The RO concentrate system was designed to reduce the
19 Carollo Engineers
Colorado River
30
2.5 mgd waste stream from the facility with a total system recovery of 94 percent. Key constituents in
the RO concentrate that were considered when selecting the treatment approach included calcium,
silica, sulfate, alkalinity, and TOC.
The pellet softening system targets the removal of calcium with the added benefit of producing calcium
carbonate pellets that are easily dewatered and result in a revenue stream that can be sold for a variety
of uses (e.g., concrete block manufacturers and specialty mineral suppliers). The clarifier stage
removes magnesium and SiO2 that can scale downstream filters and secondary RO. Media filtration
removes carryover particulates prior to the secondary RO system that benefits from the removal of
scaling minerals. The consumption of electricity for the concentrate treatment process is
approximately 1,350 kilowatts at peak treatment. The cost of the project cost was $50 million and it
has been online since May 2017.
Table 11 Chino II Concentrate Reduction Facility Project.
Capacity 20.5 MGD
Treatment train Raw water (groundwater)
RO
Ion exchange
Demineralization
Potable water
Brine treatment
Recovery ratio Before installation of demineralization :83.5%
After installation of demineralization : more than 94%
Power
consumption
1,350 kW (demineralization, maximum)
Cost CAPEX (demineralization) 50 million USD
OPEX 6.8 million USD/year
31
Figure 16 Overall Treatment Process Flow Diagram for Chino II Desalter with Flow Rates from
Each Process
Figure 17 Chino Concentrate Reduction Facility Schematic
Low-Pressure RO High-Pressure ROPre-Treatment
Chino Desalter II
High-Pressure ROPre-Treatment
Low-Pressure RO
32
This F/S uses the results of Chino project for the reference regarding technology and cost.
There is strong restriction in the inland area of Nevada that emitting brine cannot be disposed to ocean.
Table 12 Comparison between Chino project and the F/S
Step
Project
Demineralization
(1)
Water softening
treatment
Demineralization
(2)
Brine treatment
Chino Low-Pressure RO Pellet Softener
Clarifier
Media Filtration
High-Pressure RO Release
F/S Low-Pressure RO Crystellizer High-Pressure RO
ELS1
ELS2
Evaporator
33
③ Henderson - Nevada
City of Henderson is located in the metropolitan area of Las Vegas, Clarke County, Nevada. It has the
second largest population next to the City of Las Vegas. Population density and growth rate in the Las
Vegas metropolitan area is very high.
Colorado River is also the states border between Nevada and Arizona, and Hoover Dam in the Mead
Lake has been operated for the power and water supply projects. The City of Henderson is very near
from the dam.
Figure 18 Location of the City of Henderson
In the South Nevada, Return-Flow Credits project has been operated to satisfy water demand
increasing along with population growth. For the project wastewater and water reclamation facilities
of Henderson are used for keeping the water flow.
More than 600 thousand tons of treated water by advanced methods are disposed daily for keeping the
water flow, which dominates more than 40% of water supply.
That is, the characteristics of the water usage in the City of Henderson is hydrological circulation that
does not depend on much groundwater. In the sewage treatment facility there is no membrane
treatment.
Colorado River
Hoover Dam
34
Table 13 Water reclamation facility in the City of Henderson
Capacity Maximum design capacity 32 MGD
Current Capacity 22 MGD
Treatment train Raw water
Screen
Adjusting tank
Aeration tank
Sedimentation tank
UV
Disposal
Irrigation
Future plan of waste treatment is as follows:
There is no plan of introducing advanced treatment in the next 25 years under the new
masterplan of the city;
There is no motivation to introduce RO membrane because of expensive electricity cost;
Water quality of the Mead Lake has getting worse (TDS is about 600 ppm); and
Quality of disposed water remains class D (for irrigation), but there is no requirement to
introduce advanced treatment that meets class A or A+.
Therefore, there is no feasibility to introduce the project after the F/S for the time being. However,
TDS of supplied water is very high (approximately 600 mg/L), then there would be concern it is not
enough to continue water treatment by using current facilities.
35
④ Reno - Nevada
City of Reno is a city in the U.S. state of Nevada, located in the western part of the state, approximately
22 miles (35 km) from Lake Tahoe. It is the county seat of Washoe County, in the northwestern part
of the state. The city sits in a high desert at the foot of the Sierra Nevada and its downtown area (along
with Sparks and other suburbs) occupies a valley informally known as the Truckee Meadows.
Reno is the third-most populous city in Nevada after Las Vegas and Henderson and the most populous
city in the state outside the Las Vegas Valley. Reno is part of the Reno–Sparks metropolitan area,
which consists of all of both Washoe and Storey counties.
Different from the Southern Nevada, Reno is very far from Colorado River, and extremely dry inland
area.
Figure 19 Location of Reno
Reno depends on groundwater as potable water resources, and hencethe city has been investigating to
implement IPR project.
There are four water reclamation plants in Reno, and in the socond largest plant South Truckee
Meadows Water Reclamation Facility that has capacity of 3.8 MGD, the demonstration project for the
advanced water treatment has been operated:
Second treatment water is kept in the reservoir followed by usage for irrigation or agriculture.
36
Tertiary treatment water is used as raw water for the following demonstration project:
Table 14 Treatment process of the Reno demonstration project
No. Treatment Stakeholder
1 Pre-treatment (incl. tertiary treatment) Xylem (US)
2 IPR by Ozone-BAC Xylem (US)
3 UV-AOP (under construction) Trojan (Canada)
Capacity 8 GPM
Investment About 7.5 million USD
Demonstration period 7 years
(source: Northern Nevada Indirect Potable Reuse Feasibility Study)
Figure 20 Demonstration facilities (1)
Figure 21 Demonstration facilities (2)
37
Figure 22 Demonstration facilities (3)
38
2.Grasp the state of treatment of RO membrane concentrate wastewater
In the previous chapter, we confirmed policy trends related to water recycling / sewerage regeneration
processing in the United States, and it was confirmed that IPR and DPR using RO membranes in the
US are being studied in many cases. Among them, the treatment method of RO concentrated water
differs greatly between coastal area and inland area, which can result in considerable impact on cost
as well.
2-1 Processing method
Concentrated water discharged from the RO membrane when using RO membranes in IPR and DPR
is generally discharged to rivers and sea areas in coastal areas. However, when discharged to the river
in the inland area, the ion concentration of the river water increases and there is a problem that it is
difficult to take the drinking water in the downstream part of the river. In other words, considering the
water quality of intake in the inland area, it becomes difficult to discharge the RO membrane
concentrate in the river, and in order to adopt the RO membrane, it is essential to reduce the
concentration of the concentrated water.
As shown in the figure below, in the RO membrane, the pressurized feed water is concentrated on the
RO membrane surface, and the treated water flows to the central collecting pipe and is used as
permeated water. Meanwhile, in the case of seawater, the concentration of concentrated water is about
35% recovery to fresh water and about 75% recovery rate, concentrating rate is 1.5 times to 4 times
concentration on the membrane surface, and ionic components (chloride ion, total hardness,
evaporation residue) etc. are drained to the concentrated water side. This concentrated drainage is an
issue.
As mentioned above, in the United States there is a case (Chino City) where the recovery rate of the
RO membrane is enriched to 97% or more, and as shown below, ZLD (Zero Liquid Discharge) using
the Evaporator, Lime softener, Crystallize has been achieved.
39
Figure 23 RO membrane treatment
※ Evaporator: Equipment with the function of evaporating solids or
liquids
※ Lime Softener: Add lime water (calcium hydroxide) and remove hardness
(calcium and magnesium) by precipitation.
※ Crystallizer: Crystallization by condensation, crystallization by
condensation, crystallization by cooling, crystallization by
chemical reaction or equilibrium transfer.
ZLD (Zero Liquid Discharge): To reduce the risk of water pollution to realize water
circulation and to reduce waste water treatment to zero
liquid waste from the viewpoint of regeneration and reuse
of wastewater.
In the case of Chino City (Figure 16, Figure 17), crystallization is performed using ion exchange resin,
pellet softer, clarifier, etc. to achieve ZLD. In these systems, it takes time to transport chemicals in
stock (alkaline agent, lime, carbon dioxide) indispensable for device reaction from the outside, and
such consumable chemical cost is a heavy burden.
2-2 Application in this study
In this study, it is investigated that monovalent ions are concentrated through an electrolyzer systems
(ELS) as an effective utilization of RO membrane brine to achieve Zero Liquid Discharge (ZLD), and
valuable chemicals such as HCl, NaOH, NaClO and the like are produced by electrolysis (EL) and
40
utilized.
We aim for Zero Chemical Charge (ZCC) concept by on-site production and consumption without
these ZLDs or transporting water treatment chemicals from outside.
41
3.Concept of proposed system and confirmation of superiority
3-1 Purpose
In Chapters 1 to 2, it turned out that there are many areas where RO membrane processing has already
been introduced or has a plan to be evaluated in the introduction of IPR / DPR in the western United
States.
Based on this, we propose a system that can demonstrate Japanese technological superiority, and
examine its feasibility and effectiveness quantitatively. Although the effectiveness of RO membrane
treatment can be fully understood from the results in the United States, it is considered that it is a task
to eliminate concern about RO membrane concentrated water treatment in the inland area.
At present, UNR (Nevada University of Reno) and NWII (Nevada Water Innovation Institute) are
being engaged in demonstration projects of advanced treatment by using Ozone + Biologically Active
Carbon (O3+BAC) as IPR at Reno City 's wastewater treatment facility STMWRF (South Truckee
Meadows Water Reclamation Facility). In this survey, we will consider the acceptability of RO
demonstration at the site.
① Features of the proposed technology having the advantages of Japanese technology
In this survey, we propose and examine a new technology combining RO membrane treatment and
electrolysis that produces chemicals on-site to the IPR/DPR facility to the US, to actually operate
Japanese technology in the United States or the other overseas in the future on the premise that
deployment becomes possible.
② Trends in the United States
There are a large number of examples adopting RO membranes in the IPR/DPR business in the United
States, mainly in the western United States, including California where IPR projects have been
promoted advancedly. California's IPR project aims to drink water from groundwater recharge
dependent on soil adsorption and geological filtration, as well as discharging regenerated water to a
reservoir. In September 2016, following a two-year deliberation by The State Water Resources Control
Board, the report on DPR has been announced, and it is concluded that it is possible by appropriate
regulation and control on the use of sewage-derived regenerated water. Based on that, the state is
considering concrete regulations for realizing DPR .
42
Since there is almost no case of ozone treatment on the west side, it is understood that the treatment
by the RO membrane method is suitable for IP
③ Research policy
The inland IPR/DPR in the western United States will be possibly compared with ozone + bio activated
carbon, which is demonstrated in Reno City. Although it may be inferior in terms of cost (initials and
running), (1) it is possible to greatly reduce the volume of RO membrane concentrated water, (2)
considering that the underground water quality of the future can be maintained by underground
infiltration of RO membrane treated water. The ZLD method of concentrated water in RO membrane
treatment proposed in this survey will be an effective solution.
④ IPR business in RO membrane processing in the US
In the United States, the world's largest IPR in Orange County, California, carries out treatment of
378,500 m³/d (100 MGD), and the effectiveness of RO membrane treatment has been recognized.
However, at the same facility, there are aspects that are realized by permitting release of concentrated
water in the RO membrane treatment.
In this survey, a processing system corresponding to the inland western part of the United States was
examined.
⑤ ZLD + ZCC at RO membrane in Reno City or inland west US
In this survey, we examined the ZLD + ZCC system consisting of four kinds of RO membrane
treatment + electrolysis technology.
Thanks to Japan's technological superiority and new technology, we realized volume reduction by over
98% recovery (ZLD) and local generation and local consumption (ZCC) of chemicals by electrolyzing
and producing valuables from RO membrane concentrate, which has never been realized.
⑥ Results of examination in this survey
Following features are selected as the water quality condition.
43
IPR: 98.13 m3/h
TDS: 500 mg/L
A. ZLD flow
Outline of solution flow in B 'plan (Figure 24), which was selected as a suitable method, is explained
as below; treated water of RO1st is sent to underground infiltration, and concentrated water is sent to
CR (crystallizer). Part of the scale component is precipitated and separated by CR and the concentrated
water is sent to ELS1 and RO2nd. The concentrated water removed multi-valent ions by mED and is
sent to ELS2 and the water remaining multi-valent ions to RO2nd.
Acid and alkali are produced in EL and used in this process. Sending RO2nd treated water to
underground infiltration, and sending the concentrated water from RO2nd to RO3rd. Sending treated
water of RO3rd to underground infiltration, and sending concentrated water to EVA (evaporator).
Figure 24 Outline of B’ plan
44
B.Chemicals specification produced by EL in B’ plan
Table 15 Examples of HCl and NaOH quality produced through electrolysis
Chemicals HCl NaOH
Raw water Flow rate
(m3/H)
Concentration
(mg/L)
TDS
(mg/L)
Flow rate
(m3/H)
Concentration
(mg/L)
TDS
(mg/L)
TDS500 1.8 338 6,490 0.9 1,017 8,270
The quality of chemicals is listed in Tables 15 and 16. As an option, sodium hypochlorite is able to
produce (Table 16).
Table 16 Examples of NaOCl quality produced through electrolysis
Chemicals NaOCl
Raw water Flow rate
(m3/H)
Concentration
(mg/L)
TDS
(mg/L)
TDS500 2.7 1,894 7,380
C.CAPEX・OPEX
The typical CAPEX and OPEX of B’ plan are listed in Tables 17 and 18.
Table 17 CAPEX
CAPEX
Flow rate: 100 m3/H
TDS:500 mg/L
B’ Plan ZLD
(Efficiency: 98%)
RO 1.26M$
CR(Crystallization) 0.13M$
EVA(Evaporator) 1.34M$
45
ELS1 0.42M$
ELS2 0.34M$
Others 0.78M$
Total 4.26M$
Table 18 OPEX
OPEX
Flow rate: 100 m3/H
TDS:500 mg/L
Plan B’ ZLD
(Efficiency: 98%)
RO 0.112$/m3 0.423M$/MGD
CR(Crystallization) 0.023$/m³ 0.087M$/MGD
EVA
(Waste: 40ton/month) 0.185$/m³ 0.700M$/MGD
ELS1 0.01$/m³ 0.038M$/MGD
ELS2 0.095$/m³ 0.359M$/MGD
Other 0.175$/m³ 0.661M$/MGD
Power Consumption 0.098$/m³ 0.371M$/MGD
Total 0.600$/m³ 2.639M$/MGD
46
3-2 Four types of plan review
We adopted 4 plans describe here, aiming at ZLD (Zero Liquid Discharge) and ZCC (Zero Liquid
Discharge) in sewage regeneration treatment process. Among them, as a conclusion, we selected the
B 'plan was selected.
A plan (Figure 25 Outline of A plan)
Features: Supplying water to low-pressure RO membrane treatment, high pressure RO membrane
treatment, and NF membrane treatment, and then supply the NF membrane treated water to EL.
Underground penetration is 96% as efficiency, and it is possible to generate sufficient amount of
chemicals as well.
Background: Concentrating water efficiently by two-stage RO membrane treatment, water
production of monovalent ions with NF-treated water with NF membrane, conducting electrolysis
by EL.
Evaluation: In the NF membrane treated water, the separation characteristic of divalent ions has
not reached the level required by this system, and so actual operation is difficult at present.
Figure 25 Outline of A plan
47
B plan (Figure 26 Outline of B plan)
Features: In order to raise the subsurface penetration rate efficiently, investigate a crystallizer
for the need to raise the recovery rate of high pressure RO membrane treatment. In addition, it
conducts underground infiltration of 96% in a mechanism that concentrates and returns divalent
ions to raw water.
Background: Since the background that we could not satisfy the water quality requested by EL
in A plan, we introduced ELS1 with selection system that can efficiently concentrate
monovalent ions. Furthermore, a crystallization process was introduced to prevent scaling due
to calcium to each device and membrane.
Evaluation: Because of the return water from ELS1, high load was imposed on low pressure RO
membrane treatment and calcium precipitation in EL was concerned, it was judged not to be
suitable for long-term stable operation.
Figure 26 Outline of B plan
48
C plan (Figure 27 Outline of C plan)
Feature: Construct a system that can generate valuable materials with low pressure RO
membrane treatment and a simple configuration of ELS1. All chemicals generated by EL can be
used externally, with 80% results for underground penetration.
Background: Considering the case where valuable materials are generated with the highest
priority. Although the mechanism is simple, the rate of underground penetration which is the
original purpose is decreasing.
Evaluation: It is unknown whether generated acid, alkali, etc. are used as valuables without
excess or deficiency, it is judged difficult from the direction of local generation and local
consumption.
Figure 27 Outline of C plan
B’ plan (Figure 28 Outline diagram of B’plan)
Features: Efficiency of underground penetration is the best, achieving 98%. In addition,
valuable materials are generated and consumed locally in the processing process or requiring
the necessary amount.
Background: To reduce the scale of the low-pressure RO membrane treatment that was an issue
and to improve the quality of water supplied to the EL, the crystallization treated water is
49
supplied to the ELS1, and the concentrated water of the ELS1 is returned to the raw water
feeding to medium pressure RO processing without returning to RO1st is solved.
Evaluation: Although the load of RO2nd is heavy and the treated water efficiency decreases,
introduction of RO3rd is expected to lead to the merit of introducing ELS1 and 2.
Figure 28 Outline diagram of B’plan
Explanation of symbols:
A : Raw water of RO1st
B : treated fresh water at RO1st
C : Concentrated wastewater at RO1st
D : raw water for crystallization
E : outlet water for crystallization
N : acidic water produced by EL
O : alkaline water produced by EL
H : treated fresh water at RO2nd
J : Concentrated wastewater at RO2nd
K : treated fresh water at RO3rd
L : Concentrated wastewater at RO3rd
Z : Total fresh water
R : Na/Ca molar ratio of D
50
3-3 Estimation result of plans
Comparison of proposed plans is summarized in Table 19. In this survey, we adopted the B' plan as
the ZLD + ZCC plan with high applicability and versatility.
Table 19 Comparison of proposed plans
Plan Features Evaluation Score
A plan The NF membrane is installed as the
second stage of the RO2nd stage
treatment, and the concentrated water is
supplied to the ELS to produce
chemicals.
The separation characteristics of
divalent ions in the NF film have not
reached the level required by this
system.
poor
B plan Ca is removed at CR, a part of the
concentrated water is concentrated with
ELS1 supplied to ELS2, and chemical is
generated by electrolysis. ELS1
desalinated water is reprocessed at RO1st
in addition to souce water.
Although the treated water efficiency is
high, the load on RO1st is large and the
Ca load in ELS2 is large, so it was found
that it is not suitable for long-term
stable operation.
fair
C plan Supply concentrated water generated by
RO to ELS1 + ELS2, and all chemicals
generated by electrolysis are used
externally.
It is doubtful whether the generated
acid, alkali, hypochlorous acid, etc. can
be used as valuables without excess or
deficiency.
poor
B' plan Ca is removed at CR, the RO1st brine is
again concentrated with ELS1, and
chemicals are generated by electrolysis in
ELS2. ELS1 diluted water is treated at
RO2nd + RO3rd.
Although the load of RO2nd is large and
the recovery efficiency decreases,
introduction of RO3rd is expected to
attain high efficiency. There is
limitation for source water quality.
good
CR(Crystallization)、ELS1(Electrolyzer)、ELS2(Electrolyzer)
51
Figure 29 Detailed flow of B 'plan
In the trial calculation of the B 'plan, we describe here, the purpose and effect of the principal
constituent devices, the explanation of the outline processing flow, the reaction in crystallization, the
raw material water quality used for investigation, and the calculation method of EL electrolysis cell
characteristic value.
We also examined the potential use of chemicals and equipment synthesized in this survey.
Detailed flow of B 'plan is illustrated in Figure 29.
ELS1
ELS2 ELS2’
Feed Tank
Treated Tank
Feed Tank
52
3-4 Estimated result of B’ plan
① Cost
Table 20 CAPEX
Flow rate:100 m3/H
TDS:500 mg/L
B’ Plan ZLD
(Efficiency: 98%)
RO 1.26M$
CR 0.13M$
EVA 1.34M$
ELS1 0.42M$
ELS2 0.34M$
Other 0.78M$
TOTAL 4.26M$
Table 21 OPEX
Flow rate: 100 m3/H
TDS:500 mg/L
B’ Plan ZLD
(Efficiency: 98%)
RO 0.112$/m³ 0.423M$/MGD
CR 0.023$/m³ 0.087M$/MGD
EVA(Waste: 40ton/month) 0.185$/m³ 0.700M$/MGD
ELS1 0.01$/m³ 0.038M$/MGD
ELS2 0.095$/m³ 0.359M$/MGD
other 0.175$/m³ 0.661M$/MGD
Power Consumption 0.098$/m³ 0.371M$/MGD
TOTAL 0.600$/m³ 2.639M$/MGD
53
② Power consumption
Table 22 Power consumption
③ Detailed specification
Raw water condition : TDS500mg/L, 100m3/H, 24h/d
Electricity : ¥10/kWh
RO1st (low pressure)
CAPEX : 0.75M$
OPEX (inlet 100m3) : 0.257M$/MGD
Power consumption (kW) : Feed pump, 5.5kW×3, 556L/min×25m
RO1st high pressure pump, 15kW×3, 556L/min×80m
RO type : TMG 20-400
RO effective area :4,440m2(120pcs)
Others : CAPEX included
4 units
Vessel (3m):10pcs/Unit
RO membrane:30pcs/unit
RO pieces :120pcs
Flow rate: 100 m3/H( 0.634 MGD)
TDS:500 mg/L
Plan B’ ZLD
( Efficiency 98%)
RO 89.4kW
CR 4.5kW
EVA 72kW
ELS1 63.4kW
ELS2 10.5kW
Others
(Injection pump, Chemical pump) 5.5kW
Total 245.35kW
54
OPEX included RO membrane exchange fee
Crystallizer
CAPEX : 0.13M$
OPEX (inlet 100m3) : 0.087M$/MGD
Power consumption (kW) : Blower, 1.5kW×1, 65L/min×0.78MPa
Recycle pump, 1.5kW×1, 200L/min×25m
Slurry, 1.5kW×1, 150L/min×12m
Others : -
ELS1(Electrolyzer)
CAPEX : 0.42M$
OPEX (inlet 100m3) : 0.038M$/MGD
Power consumption (kW) : ELS1 Feed pump, 1.5kW×1, 520L/min×10m
ELS1 treating pump, 0.4kW×1, 200L/min×8m
ELS1 condensation pump, 1.5kW×1, 45L/min×20m
ELS1, 60kW×1
Current efficiency : 90%
Flow rate : 25m3/h
Service life : 7-8 years
Power consumption : 0.6kWh/ton
Power supply : max DC10V
Current : max 0.1A/cm2
Others : OPEX included
Membrane exchange fee
ELS2(Electrolysis)
CAPEX : 0.34M$
OPEX (inlet 100m3) : 0.359M$/MGD
Power consumption (kW) : ELfeed pump, 0.75kW×1
Feed pump 1, 0.4kW×1
Feed pump 2, 0.4kW×1
EL、9.0kW×1
Current efficiency : 90%
Service life : 3-4years
Power supply : max DC10V
55
Current : max 0.2A/cm2
Others : OPEX included electrodes exchange
RO2nd (Middle pressure)
CAPEX : 0.28M$
OPEX (inlet 100m3) : 0.117M$/MGD
Power consumption (kW) : Feed pump, 3.7kW×1, 520L/min×20m
RO2nd high pressure pump, 11kW×1, 520L/min×200m
RO type :TM720-400
RO effective area :1998m2(54pcs)
Others : CAPEX included
2 Units
Vessel (3m):9pcs/Unit
RO membrane:27pcs/unit
RO pieces:54pcs
OPEX included RO membrane exchange fee
RO3rd (High pressure)
CAPEX : 0.24M$
OPEX(inlet100m3) : 0.049M$/MGD
Power consumption (kW) : Feed pump, 2.2kW×1、130L/min×20m
RO3rd high pressure pump, 11kW×1、130L/min×200m
RO type :TM820C-400
RO effective area :740m2(20pcs)
Others : CAPEX included
2 Units
Vessel (2m):5pcs/Unit
RO membrane:10pcs/unit
RO pieces :20pcs
OPEX included RO membrane exchange fee
EVA(Evaporator)
CAPEX : 1.34M$
OPEX(inlet100m3) : 0.700M$/MGD
Power consumption (kW) : EVA, 72kW
Others : OPEX included gel type waste disposal for 40 ton/month.
56
Others
CAPEX : 0.78M$
OPEX (inlet 100m3) : 0.661M$/MGD
Power consumption (kW) : Electricity in mechanics:<1kW
Injection pump, 5.5kW×1, 1650L/min×12m
Others : CAPEX included
Chemical pump unit
Control panel
Mechanical room
Construction
Transfer fee
others
OPEX included
Cartridge filter
Water analyzing fee
TOTAL
CAPEX : 4.26M$
OPEX(inlet100m3) : 2.268M$/MGD (0.53M$/year)
Power consumption (kW) : 245.35kW (0.371M$/MGD)
57
Table 23 Summary of RO membrane with required pump specification.
58
3-5 Summary
Based on the technical characteristics of the B 'plan, we conducted an investigation and examined the
profitability and treated water quality. Specifically, in order to compare with the HERO ™ process
(described below), the concentration of alkali and acid to be used and the amount of water should be
determined based on the capability of ELS1 and ELS2 with their cost on the premise that it satisfies
the total amount required for the process.
* The HERO™ process prevents all scale/fouling factors (hardness, alkalinity, silica precipitation,
organic fouling, biofouling) by ion exchange resin, degasser, high pH operation, and the entire
RO system technology to maximize recovery. HERO: High Efficiency Reverse Osmosis
(1) Conclusion
Examples of performance results based on trial calculations of the proposed B 'plan shown in Figure
30 are shown in Tables 24 and 25. The types and concentrations of the chemical solutions produced
by the electrolysis are shown in Tables 26 and 27. We examined 4 plans of A, B, C, and B’ by this
survey as shown in Figs. 25-28. The comparison of the proposed plans is shown in Table 19 of section
3-3.
① In the comparison between Capex and Opex between conventional chemical purchasing method
and electrolyzer (ELS1 + ELS2) introduction method in RO + CR system, in the region where
TDS is 500 or more and chemical price is 400 yen / kg or more, recovery period Was almost 20
years, and the profitability of the proposed method was confirmed (chemical purchasing cost>
onsite manufacturing cost).
② In the B 'plan, there is concern about a decline in the recovery rate of treated water, but feasibility
is high within a limited range. By installing RO3rd, the recovery rate can be improved and a result
of 98% or more can be expected.
59
Figure 30 Flow diagram of B’ plan
Table 24 Example result of power consumption estimation
ELS1
ELS2
60
Table 25 Example result of mass balance estimation
Table 26 Chemical quality of HCl and NaOH produced through electrolysis
Chemical
type
HCL NaOH
concentration amount
(㎥/H)
concentration
(mg/L)
quality
(TDS)
amount
(㎥/H)
concentration
(mg/L)
quality
(TDS)
TDS250 1.8 169 3245 0.9 462 4135
TDS500 1.8 338 6490 0.9 1017 8270
TDS1000 1.8 676 12980 0.9 1848 16540
TDS1500 1.8 1014 19470 0.9 2772 24810
Table 27 Chemical quality of HCl and NaOH produced through electrolysis
Chemical type NaOCl
concentration amount (㎥/H) concentration (mg/L) quality (TDS)
TDS250 2.7 861 3690
TDS500 2.7 1894 7380
TDS1000 2.7 3442 14760
TDS1500 2.7 5164 22140
※ Purity level is expressed based on TDS.
※ It is possible to produce NaOH and NaOCl at the same time, however, its process is not applied
for this survey.
61
(2)Main devices constituting the B 'plan
The main devices and roles that make up B 'plan are described below (Table 28).
① RO (Reverse osmosis): Low pressure type (removal rate: 97%) in the first stage (RO1), medium
pressure type (removal rate: 97%) in the second stage (RO2), high pressure type (removal rate:
99.5%) (RO3) are used to separate ionic substances, and fresh water is obtained. The valuable
substances are recovered from the concentrated water obtained from the first stage RO1. This is
an indispensable device. At this time, TMG 20-400 manufactured by Toray Industries, Ltd. was
selected as the low pressure RO1 for concentration by the reverse osmosis membrane. Operation
with high recovery at low pressure and membrane area are large and efficient treatment water
volume can be ensured. Selection of RO membrane and selection of high pressure pump in B
'plan are as shown in Annex Table 6. Selection of pumps, power consumption and installation
area in each TDS are described Annex Tables 3 to 5.
② CR (Crystallization): CaCO3 is removed by alkali addition (then NaHCO 3 is formed) in CR
apparatus. It is also an essential device regardless of source water.
③ ELS (Electrolysis): In order to reliably proceed the crystallization reaction, high concentration
of alkali is produced by ELS device. On the other hand, produced acid in EL is used to maintain
the water quality after crystallization at an appropriate pH (about 10), regular cleaning of EL
cathode chamber, RO equipment and so on. Excess chemicals can be used for other purposes,
and it is an indispensable device regardless of the quality of source water.
62
Table 28 Plan Features and strengths Role of processing equipment
Figure 31 Example of B’ plan flow diagram
63
As the flow rate, concentration and substance amount of each point, for example, in A, the flow rate
is expressed as VA (m3/h) concentration CA (g/m3 = mg/L) and the substance amount Q (g/h) when
specifying Na ion at point A, the component included in VANa (m3/h) concentration CA
Na is described
as the component contained in the sample.
Q = V × C
As the amount of water, the following holds.
VG = VE-VF+VW
VZ =V B-VM+VH+VK
VF = VE-VG + (a part of water N)
VN = 2VW/3
VO = VW/3
CECa = CD
Ca/2 (assumption in trials a and c) or CDCa/3 (assumption in trial calculation b)
The branching rate of E water as F water is determined by the amount necessary and sufficient for
preparing the alkali amount NaOH required for crystallization by EL. In the trial calculations in this
survey, this was taken as 1, and all E water was taken as F water.
VE = VF
The separation factor in RO1 was set at 4.
The following is established as the material balance.
QA = QB + QC
VA = VB + VC
VA×CA = VB×CB + VC×CC
In electrodialysis, the concentration of the substance permeating the membrane is q times (q = 3 - 5
for monovalent ions, Ca is 1.5). q depends on substance.
CY = q CX
On the other hand, the concentration of substances that do not penetrate the membrane hardly
changes.
64
CW = CF
(3) Outline of processing flow
The outline of the flow diagram in the B 'plan is described below.
① Add an appropriate amount of acidic water (adjusted with a pH meter) in order to lower a part
of the water E after crystallization to pH 8 or less, and supply it to the ELS1 diluting chamber
② Branch a part of the water F, dilute it with RO1 treated water and make it water X, and supply
it to the ELS1 concentrating chamber (chamber where salt concentration increases by dialysis).
If using the water produced by branching a part of the concentrate instead of the water F,
pathogens existed in RO1 concentrate will not remain in the water. There is a fear that
pathogenic bacteria may remain in demineralized water of mED, but it can be separated by RO2.
③ In mED, bicarbonate ion exists under neutral condition. In the concentrating chamber, the
concentration of only monovalent ions increases (Na+, Cl-, HCO3-ion, etc. Ca ions also
concentrates at moderate rate in spite of divalent ion, refer to Table 29), and in the desalting
chamber the concentration of only divalent ions (SO42- ions etc.) is maintained. The desalting
chamber water is used as a part of raw material of water G (RO2 inlet solution).
④ The concentrate water subjected to the electrolytic treatment with ELS1 is supplied to the
diaphragm type electrolysis cell, ELS2. 1/3 of the concentrate is supplied to the cathode
compartment (alkaline water is synthesized by electrolysis) and 2/3 is supplied to the anode
compartment (synthesis of acid water by electrolysis). This is to suppress the migration of protons
to the cathode compartment (due to concentration polarization and electrophoresis) by the pH
reduction of the anode compartment. The proton transport rate is specifically large among the ion
and can be avoided by the recombination reaction (neutralization reaction) of protons and
hydroxyl ions by keeping it below the appropriate decomposition rate (33%). Salt decomposition
rate can only be raised to around 33%. Tables 29 and 30 show the iInfluence of impurities for ion
exchange membrane electrolysis.
65
Table 29 Influence of impurities for ion exchange membrane electrolysis①
Table 30 Influence of impurities for ion exchange membrane electrolysis②
66
⑤ In the electrolytic chamber of EL, water N which is acidic water and water O which is alkaline
water are generated. Ca ion concentration should be 100 mg/L or less. By using a neutral
diaphragm, it can be inferred that the effect of clogging due to precipitation of hardness
component in the membrane is relatively unlikely. The hardness component also precipitates on
the cathode, but its effect on the electrolytic performance is moderate. If the voltage rises, the
performance intermittently recovers by washing with acidic water (acidic water N produced in
the anode chamber).
⑥ Acidic water N supplies the amount of water to be supplied to RO2 water to be reduced to about
pH 10. This is to keep the silica ionic and to improve the removal performance of RO2. It can
be used when it is necessary to neutralize the pH of the final concentrated water and or to adjust
the pH of the feed water of RO1.
⑦ Water K is mixed with RO1 concentrated water C to become water D before crystallization.
CaCO3 is precipitated and separated by the equation (1) shown later. In order to proceed with
the reaction, the target of pH of water L is 10.3 or higher. In order to proceed the equilibrium
reaction (1), it is necessary to set Na/Ca> 1 as the water D quality.
⑧ Although hypochlorous acid can be produced by ELS, it is not a main target product in this
investigation, so it will not be manufactured here. However, when it is expected to be used in
the preceding and succeeding water treatment processes, it can be synthesized by ELS. The pH
of the anode chamber is around 2, and generation as chlorine gas as free chlorine is assumed.
(4) Reaction in crystallization (CR)
The substances involved in the Ca separation reaction in crystallization are listed in Table 31. The
precipitation of CaCO3 is based on the following equilibrium equation (1). The relationship between
pH and existing ion form oc carboneous ions is shown in Figure 32.
Ca(HCO3)2 + NaOH = CaCO3↓+ NaHCO3 + 2H2O (1)
67
Figure32 Equilibrium relationship between pH
and carbonate compound
Table 31 Solubility
(5) Calculation method of EL characteristic value
① Cell voltage
The cell voltage V is expressed by equation (2).
V = V 0 + Σ η + Σ IR (2)
(V0: the sum of the equilibrium electrode potential difference and the membrane potential of
oxidation/reduction reaction, Σ η: the sum of each electrode reaction overvoltage η, Σ IR: sum of
voltage loss IR due to solution, membrane, electrode substrate resistance)
In this case η is estimated to be about 0.3 V and 0.2 V for the anode and the cathode, respectively,
depending on the electrode material. It is presumed that the substrate resistance is negligibly small and
the membrane potential is negligibly small.
Conductivity σ (S/cm) was obtained in the RENO analysis result with chloride ion concentration of
15 mg/L (0.015 w/v%) and TDS = 250 having 0.4 mS/cm. A similar relationship (3) holds even in raw
water.
σ = 18.1 × C (w / v%) (3)
At 300 mg/L, σ is 20 times, and resistivity ρ (Ω cm) is 1/20. Among the EL cell voltages, the solution
resistance voltage loss VIR (V) is defined as the current density j (A/cm2) and the inter-electrode
distance d (cm),
68
VIR = j d ρ = j d / σ (4)
Here, d is fixed at 0.2 cm. The resistance loss due to the diaphragm is added to this, but it is not
considered that the resistance loss is smaller than the solution resistance one. The j is set within the
range of 0.05 to 0.3 A/cm2 in ordinary industrial electrolysis (other than salt electrolysis), and constant
current operation is performed. It is necessary to set the cell voltage to 10 V or less.
The theoretical decomposition voltage V0 of water electrolysis is 1.23 V at room temperature,
assuming that the pH of the anode chamber and the cathode chamber is neutral, but in practice the pH
of each solution is about 2, 12 respectively, and considering this gives,
V0 = 1.23 + 0.059 × 10 = 1.82 V (5)
An overvoltage of 0.5 V (constant for simplicity) is added to this. The voltage loss of the separator is
added. In order to suppress corrosion of materials used, it is necessary to set the cell voltage to 10 V
or less.
The current value required for electrolysis was conditioned on decomposition of one-third of the inlet
concentration of EL (salt decomposition percent is 33%).
③ Current efficiency
Assuming that the current efficiency of the target substance is Ce (%), the power consumption unit Pc
(Wh/g) is expressed by the equation (5).
Pc = 100 n F V / (3600 Ce M) (6)
(M: molecular weight of product substance, n: electron number, F: Faraday constant)
Current efficiency is important from the viewpoint of economy, and it is a characteristic greatly
dependent on the cell structure. In addition, side reactions for non-current efficiency decrease product
purity, and in some cases post-treatment for product separation cannot be ignored. In this FS case, the
current efficiency is 90% and the salt decomposition percent is 33%. The liquid flow rate on the anode
side was doubled, and it is assumed that there is no side reaction and the current efficiency was
equivalent inboth the anode chamber and the cathode chamber.
69
(6) Calculation result (assuming that introduction of ELS and comparison with
purchasing chemicals, other systems such as RO are equivalent)
As described in the summary of this FS, Capex and Opex were compared between the conventional
chemical purchasing method in the RO + CR + EVA system (like as HERO) and the method in which
the electrolytic device (ELS) was introduced in the same manner.
① Reason for price calculation
a. Capex
Capex is assumed to be proportional to the flow rate, that is, 1000 m3/h is calculated as 10 times
100 m3/h. In the following results, 100 m3/h was described.
The required area, current value and pump capacity of the electrode were selected to have the
ability to synthesize the minimum amount of NaOH necessary for completion (50-67% as a result)
of the reaction in the crystallization process.
ELS includes equipment costs of accessories, tanks and pumps. Plumbing expenses, installation
costs are not considered.
b. Opex
Operating conditions were designed assuming that the required area, current value and pump
capacity of the electrode can be synthesized by electrolytic EL for the minimum amount necessary
for completion of the reaction in the crystallization process.
As an introduction merit when ELS is introduced, on the premise of introducing the crystallization
process, wherein it is necessary to prepare alkali for CaCO3 removal, and to prepare acid for pH
adjustment of raw water of ELS1 and periodic RO2 and RO3 cleaning. Each marketing +
transportation cost are used as a parameter within the range of ¥ 300 to 500/kg corresponding to
the usage amount. Here, it is assumed that all the chemicals synthesized by electrolysis are
effectively used.
On the premise of introducing the crystallization process, merit is expected that used chemicals
are reduced as waste, though the merit price was negligible.
② Raw water quality used for FS
The parameter range of the water to be analyzed is the water quality range of the area expected to be
70
installed, that is, TDS is 250, 500, 1,000 and 1,500 mg/L, the raw water flow rate is 100, 300, 500 and
1,000 m3/h.
Table 32 shows the water quality studied and the water quality and Na/Ca ratios targeted for trial
calculation, wherein SS-1 and SS-2 were mainly used.
Table 32 Source water to be evaluated
③ Selection of target water quality
The relation between the Na/Ca ratio of the source water and the Na/Ca ratio R at the entrance of the
crystallizer and the analysis range were examined. When the Na/Ca ratio of the source water becomes
large, the Na/Ca ratio at the inlet of the crystallizer also increases.
In the B' plan, most of the CR exit water is sent to the ELS1 and the demineralized water of the ELS1
is not returned to the RO1st but is supplied to the RO2nd. For this reason, the load of RO1st becomes
small (there is no reprocessing process), the water quality of RO2nd supply water is improved, and
stable operation can be expected, whereas the RO2nd water volume increases, the concentrated RO2nd
or introduce RO3rd.
Figure 33 shows the results of R (corresponding to removal performance) in CR using RO1st treated
water usage (parameter for analysis) in ELS1 as a parameter for source water A of different Na/Ca
ratios. The closer condition to the upper side of Figure 3 is, the higher the amount of precipitated Ca
in crystallization is. If the Na/Ca ratio is 0.8 or more, Ca precipitation of 50% or more can be achieved.
Based on the above, the Na/Ca ratio of source water is set to 1.33, 1, so that the removal rate in
crystallization is 0.5 and 0.67, the water supply amount and TDS at each flow lines are calculated
using the concentration rate at ELS1 as parameters.
Water qualityRENO
Tap waterUS
InlandSNWSdata
Simulated Solution-1
Simulated Solution-2
Simulated Solution-3
Carollo AMTAdata
Na (mg/L) 20 90 89 40 40 40 39Cl (mg/L) 15 92 93 75 75 75 75Ca (mg/L) 10 68 76 30 40 67 113
Alkalinity (mg/L) 120 135 140 140 140 214Ratio of Na/Ca
in Source2.00 1.32 1.17 1.33 1.00 0.60 0.35
71
Figure 33 Variation of R value at CR with Na/Ca ratio in source water
a. When the Na/Ca ratio is larger than 2, nearly complete removal of Ca in crystallization (R = 1,
provided that saturated soluble part cannot be removed) is achieved, and if necessary the alkali to
be used besides CR Can be generated. Use of this FS process with raw water having Na / Ca ratio
of 2 or more is easy. However, it can be said that the proportion occupied by the basin and the
water purification plant where such raw water is obtained is small.
b. When the Na / Ca ratio is 0.8 to 2, R = is 0.4 to 1, and removal of more than half of Ca in
crystallization is achieved. A part of Ca corresponding to the remaining solubility precipitates in
ELS1 and ELS2 cathode and diaphragm, but it is washed with acid generated by EL. As the
removal efficiency of Ca in the crystallizer is increased (corresponding to increasing the
concentration of NaOH), the required power, ELS device scale tends to increase. It is necessary
to confirm the optimum system operating condition while considering acid washing in the EL.
c. When the Na / Ca ratio is 0.8 or less, R = 0.4 or less, and the Ca separation in CR remains less
than half. The merit of introducing the crystallizer is small, and it is supposed that this FS process
cannot be applied.
③ ELS1 condensation ratio of condensation chamber (outlet/inlet)
Figure 34 shows the RO1st treated water usage relative to the ELS1 enrichment rate. The usage rate
can be reduced by increasing the concentration ratio. On the other hand, as shown in Figure 35, the Ca
concentration of the concentrated water, that is, the EL raw material water increases remarkably, and
the load on the EL increases. In consideration of these trends, the present FS calculates the
concentration rate to be 3-5 times. The goal was to set the concentration of Ca supplied to EL to control
72
at 100 mg/L or less.
Figure 34 Relationship between RO1 treated water usage and concentration ratio in ELS1
concentrating compartment
Figure 35 Relationship between Ca concentration and concentration ratio in ELS1 concentrating
compartment
④ Simulation Result
a. In the case that Na / Ca ratio is 1.33 (SS-1), the CR separation rate is 50%
In simulated solution-2 (SS-1) having 140 as alkalinity, by mixing with alkaline solution (NaOH and
Na2CO3) from EL at the CR entrance, the Na/Ca ratio increases from 1.33 to about 2. The ratio here
0
5
10
15
20
25
0 20 40 60 80
Na/Ca ratio in source water A
0.8
1.0
1.3
RO
1tr
eat
ed
wat
er M
(m
3/h
)
Condensation ratio from water X to Y in ELS1
0
50
100
150
200
250
300
350
400
0 20 40 60 80
Na/Ca ratio in source water A
0.8
1.0
1.3
Co
nd
en
sed
Ca
con
c. in
Y (
g/m
3)
Condensation ratio from water X to Y in ELS1
73
is defined as the ratio in the source water that does not contain Na ions contained in the alkali from
EL originated from the carbonate, that is, it is assumed that bicarbonate explained in (3)-7 in ELS1
done not contribute as alkaline component.
Table 33 shows changes in power consumption versus EL current density. Depending on the current
density of EL, the larger the voltage, the larger the current density. However, it is smaller than the
power consumption of ELS1 among the total power consumption.
Table 33 Change of EL power consumption with the current density based in the case of Na/Ca
ratio=1.33 (SS-1) and CR separation rate=50%
In Table 34, the depreciation period of ELS1 + ELS2 purchasing equipment was calculated as power
consumption and expendable item cost as Opex for each TDS. Figure 36 shows the result of power
consumption. As the TDS increased, the power consumption simply increased, and the power
consumption per treated water amount was represented by one straight line (Figure 37). For Capex
(Figure 38), it increased simply as the TDS increased and the depreciation period was indicated as a
parameter within the range from 300 yen/kg to 500 yen/kg for the drug unit price (Figure 39). As TDS
increases, the depreciation period is 28.1 years at TDS = 500 and 12.5 years at TDS = 1,500, when not
considering expenses related to dehydration treatment and waste treatment, improving profitability.
74
Table 34 FS result based on Na/Ca ratio=1.33 (SS-1) and CR separation rate=50% in the case of
400 yen/kg for chemicals and 10¢/kWh.
Figure 36 Dependence of electric power consumption on TDS
TD S m g/L 250 500 1000 1500
ELS1 P C (100m 3/h) kW 21.3 42.6 85.1 127.5
ELS2 P C (100m 3/h) kW 21.5 22.8 25.7 28.6
Total P C (100m 3/h) kW 42.8 65.4 110.8 156.2
Electricity total cost yen/year 3,752,758 5,729,887 9,702,307 13,678,763
C onsum ables for ELS1 yen/year 17,792 35,487 70,877 106,268
C onsum ables for ELS2 yen/year 45,291 89,955 179,284 268,613
Expense total cost yen/year 3,815,840 5,855,329 9,952,469 14,053,643
C hem icals cost (A cid & A lkali) yen/year 4,424,347 8,808,051 17,575,458 26,342,865
M erit - Expense yen/year 608,508 2,952,722 7,622,989 12,289,222
C A P EX of ELS1 & ELS2 yen 68,116,251 85,982,070 121,713,709 157,445,347
R ecover period of ELS1 & ELS2 year 103.0 28.1 15.5 12.5
0
200
400
600
800
1,000
1,200
1,400
1,600
1,800
0 500 1000 1500 2000
TDS (mg/L)
PC
(kW
)
Volume rate
1,000 m3/h
500 m3/h
300 m3/h
100 m3/h
75
Figure 37 Dependence of unit electric power consumption per 1m3 on TDS
Figure 38 Dependence of Capex on TDS
0.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
1.6
1.8
0 500 1000 1500 2000
TDS (mg/L)
kWh
/m3
0.0
2.0
4.0
6.0
8.0
10.0
12.0
14.0
16.0
18.0
0 500 1000 1500 2000
TDS (mg/L)
Cap
ex (億円
)
Volume rate1,000 m3/h
500 m3/h
300 m3/h
100 m3/h
(10^
8
yen
)
76
Figure 39 Dependence of depreciation period on TDS
b. In the case that Na / Ca ratio is 1.33 (SS-1), the CR separation rate is 67%
In Table 35, the depreciation period of ELS1+ELS2 purchasing equipment was calculated as power
consumption and expendable item cost as Opex for each TDS.
Figure 40 shows the result of power consumption. As the TDS increased, the power consumption
simply increased, and the power consumption per treated water amount was represented by one
straight line (Figure 41). For Capex (Figure 42), it increased simply as the TDS increased and the
depreciation period was indicated as a parameter within the range of 300 yen/kg to 500 yen/kg for the
drug unit price (Figure 43). As TDS increases, the depreciation period is 13.6 years at TDS = 500 and
8.9 years at TDS = 1,500, when not considering expenses related to dehydration treatment and waste
treatment, improving profitability.
0
20
40
60
80
100
120
0 500 1000 1500 2000
Chemical PRICE300 ¥/kg400 ¥/kg500 y¥kg
回収期間(年)
TDS (mg/L)
Re
co
ve
r pe
riod
(ye
ars
)
77
Table 35 FS result based on Na/Ca ratio=1.33 (SS-1) and CR separation rate=67%
in the case of 400 yen/kg for chemicals and 10¢/kWh.
Figure 40 Dependence of electric power consumption on TDS
TD S m g/L 250 500 1000 1500
ELS1 P C (100m 3/h) kW 33.0 65.7 131.7 197.4
ELS2 P C (100m 3/h) kW 14.6 17.1 22.5 27.8
Total P C (100m 3/h) kW 47.6 82.9 154.3 225.2
Electricity total cost yen/year 4,168,564 7,260,491 13,512,773 19,729,245
C onsum ables for ELS1 yen/year 27,490 54,780 109,765 164,482
C onsum ables for ELS2 yen/year 81,338 161,391 323,718 484,926
Expense total cost yen/year 4,277,392 7,476,661 13,946,256 20,378,653
C hem icals cost (A cid & A lkali) yen/year 7,947,854 15,791,366 31,685,259 47,485,594
M erit - Expense yen/year 3,670,462 8,314,705 17,739,003 27,106,941
C A P EX of ELS1 & ELS2 yen 82,535,364 114,556,223 179,487,356 243,970,433
R ecover period of ELS1 & ELS2 year 22.5 13.8 10.1 9.0
0
500
1,000
1,500
2,000
2,500
0 500 1000 1500 2000
TDS (mg/L)
PC
(kW
)
Volume rate
1,000 m3/h
500 m3/h
300 m3/h
100 m3/h
78
Figure 41 Dependence of unit electric power consumption per 1m3 on TDS
Figure 42 Dependence of Capex on TDS
0.0
0.5
1.0
1.5
2.0
2.5
0 500 1000 1500 2000
TDS (mg/L)
kWh
/m3
0.0
5.0
10.0
15.0
20.0
25.0
30.0
0 500 1000 1500 2000
TDS (mg/L)
Cap
ex (億円
)
Volume rate
1,000 m3/h
500 m3/h
300 m3/h
100 m3/h
(10^
8
yen
)
79
Figure 43 Dependence of depreciation period on TDS
0
5
10
15
20
25
30
35
40
45
50
0 500 1000 1500 2000
Chemical PRICE300 ¥/kg
400 ¥/kg500 y¥kg
回収期間(年)
TDS (mg/L)
Re
co
ve
r pe
riod
(ye
ars
)
80
c. In the case that Na / Ca ratio is 1 (SS-2), the CR separation rate is 50%
In Table 36, the depreciation period of ELS1+ELS2 purchasing equipment was calculated as power
consumption and expendable item cost as Opex for each TDS. Annex Table 12 examined the
profitability with respect to the EL current density.
Figure 44 shows the result of power consumption. As the TDS increased, the power consumption
simply increased, and the power consumption per treated water amount was represented by one
straight line (Figure 45). For Capex (Figure 46), it increased simply as the TDS increased and the
depreciation period was indicated as a parameter within the range of 300 yen/kg to 500 yen/kg for the
drug unit price (Figure 47). As TDS increases, the depreciation period is 21.1 years at TDS = 500 and
10.8 years at TDS = 1,500, it is shown that profitability improves.
Table 36 FS result based on Na/Ca ratio=1 (SS-2) and CR separation rate=50% in the case of 400
yen/kg for chemicals and 10¢/kWh.
TD S m g/L 250 500 1000 1500
ELS1 P C (100m 3/h) kW 27.0 54.7 107.6 161.3
ELS2 P C (100m 3/h) kW 29.8 32.3 35.6 39.7
Total P C (100m 3/h) kW 56.8 87.0 143.2 200.9
Electricity total cost yen/year 4,975,025 7,622,467 12,542,531 17,601,558
C onsum ables for ELS1 yen/year 22,508 45,575 89,631 134,379
C onsum ables for ELS2 yen/year 62,768 127,391 248,462 372,258
Expense total cost yen/year 5,060,302 7,795,433 12,880,624 18,108,195
C hem icals cost (A cid & A lkali) yen/year 6,137,771 12,486,122 24,381,599 36,544,152
M erit - Expense yen/year 1,077,469 4,690,689 11,500,975 18,435,956
C A P EX of ELS1 & ELS2 yen 75,107,277 100,956,401 149,384,813 198,903,171
R ecover period of ELS1 & ELS2 year 69.7 21.5 13.0 10.8
81
Figure 44 Dependence of electric power consumption on TDS
Figure 45 Dependence of unit electric power consumption per 1m3 on TDS
0
500
1,000
1,500
2,000
2,500
0 500 1000 1500 2000
TDS (mg/L)
PC
(kW
)
Volume rate1,000 m3/h
500 m3/h
300 m3/h
100 m3/h
0.0
0.5
1.0
1.5
2.0
2.5
0 500 1000 1500 2000
TDS (mg/L)
kWh
/m3
82
Figure 46 Dependence of Capex on TDS
Figure 47 Dependence of depreciation period on TDS
0.0
5.0
10.0
15.0
20.0
25.0
0 500 1000 1500 2000
TDS (mg/L)
Cap
ex (億円
)
Volume rate
1,000 m3/h
500 m3/h
300 m3/h
100 m3/h
0
10
20
30
40
50
60
70
0 500 1000 1500 2000
Chemical PRICE300 ¥/kg400 ¥/kg
500 y¥kg
回収期間(年)
TDS (mg/L)
(10
^8 y
en
)
Re
co
ve
r pe
riod
(ye
ars
)
83
⑤ Summary of calculation results
a. The depreciation period depends on the current density of EL, the more the depreciable period
decreases with the current increase, and if it raises from 0.05A/cm2 to 0.2A/cm2, the depreciation
period will be almost half (20 to 10 years). According to UNR, it was said that device profitability
would be judged in 5-10 years.
b. The larger the TDS, the higher the power consumption (processing cost per m3), which is ranged
from 0.6 to 1 kWh/m3 at TDS 500 and from 2 to 3 kWh/m3 at 1,500.
c. Capex monotonically increased with increasing TDS, which is ranged from 0.6 to 0.8 billion yen
at TDS 500 and from 1.0 to 1.04 billion yen at 1,500.
d. Among the Opex, the power consumption of the ELS1 increases according to the TDS, while the
power consumption of the EL does not increase significantly to the TDS. This is because the
larger the raw material salt concentration, the lower the resistance loss in electrolysis and the cell
voltage is reduced.
e. Though the ratio of ELS1 and ELS2 power consumptions is very large in total Opex, it was found
that there are merits of introduction.
f. The greater the TDS, the shorter the period of depreciation. This is because the amount of
production of valuable chemicals increases. It can be depreciated in 14 to 27 years at TDS 500,
and in 8 to 12 years at TDS 1500.
g. Since the depreciation period varies depending on the chemical price, the evaporation processing
cost, and the waste disposal cost, it is necessary to grasp the local price for each installation area.
h. The greater the Na/Ca ratio in the source water quality, the more Capex increases, but the period
of depreciation decreases (contrast between ④-a and ④-c)
i. The larger the Ca removal rate in CR, the more Capex increases or the depreciation years decrease
(contrast between ④-a and ④-b).
j. The chemical composition is an acid and an alkali which contain almost no multi-valence ions
84
except that Ca ions with around 100 mg/L. As the TDS concentration increases, chemicals with
higher concentration are produced. The chemical production at 100m3/h in the range of 500 to
1,500 of TDS, NaOH concentration: from 0.9 g/L to 2.8 g/L, amount: from 0.9 kg/h to 2.6 kg/h,
HCl concentration: from 0.3 g/L to 1.0 g/L, amount: from 0.8 kg/h to 2.3 kg/h. Since on-site
generated chemicals are in low concentrations. (There is no regulation, which is a major
difference from high-level purchased chemicals and merit, according to UNR comment).
k. The precipitation amount of CaCO3 in CR is in the range of 4 kg/h to 11 kg/ h.
85
4.Business model and estimate of project cost
4-1 Project cost
Project cost both in the phase of demonstration and commercial projects are estimated as follows, in
which we can find the effect of scale merit.
Table 37 Project cost
Project phase Treated amount of raw water CAPEX
(million USD)
OPEX
(million USD/MGD)
Demonstration
project
100 m3/h (0.634 MGD) 4.26 2.639
Commercial
project
1,000 m3/h (6.34 MGD) 35.55 2.615
4-2 Cost comparison
① CAPEX
Estimate of CAPEX for the commercial water reclamation project (20 MGD) is carried out as follows.
Judging only from the cost, Ozone-BAC treatment has advantage. However, the adequate cost must
be investigated considering TDS level, brine disposal etc.
Table 38 Comparison of CAPEX (20 MGD)20
Treatment method Cost (million USD) Applicability
of this F/S
Ozone-BAC 91 △
RO Treatment of brine: ocean disposal 120 ×
Treatment of brine: evaporator (mechanical) 172 ○
Treatment of brine: evaporator (ponds) 303 △
20 EPA “2017 Potable Reuse Compendium” (2017)
86
Figure 48 Comparison of CAPEX21
CAPEX estimated in this F/S is 35.55 million USD with capacity 6.34 MGD, which is compatible to
the other treatment.
Figure 49 Comparison of CAPEX with this F/S (red line)22
② OPEX
Estimate of OPEX for the commercial water reclamation project (20 MGD) is carried out as follows.
There are some restrictions against application in North Nevada, the same with CAPEX.
21 Schimmoller, L; Kealy, M.J.: Fit for Purpose Water: The Cost of Over‐treating Reclaimed Water (WRRF 10‐01). The Water Research Foundation (formerly the WateReuse Research Foundation): Denver, CO, 2014. 22 Schimmoller, L; Kealy, M.J.: Fit for Purpose Water: The Cost of Over‐treating Reclaimed Water (WRRF 10‐01). The Water Research Foundation (formerly the WateReuse Research Foundation): Denver, CO, 2014.
87
Table 39 Comparison of OPEX (20 MGD)23
Treatment method Cost (million USD/y) Applicability
of this F/S
Ozone-BAC 4.2 △
RO Treatment of brine: ocean disposal 5.9 ×
Treatment of brine: evaporator (mechanical) 10.9 ○
Treatment of brine: evaporator (ponds) 6.3 △
Figure 50 Comparison of OPEX24
OPEX estimated in this F/S is 16.58 million USD with capacity 6.34 MGD, which is much expensive
than the other treatment.
23 EPA “2017 Potable Reuse Compendium” (2017) 24 Schimmoller, L; Kealy, M.J.: Fit for Purpose Water: The Cost of Over‐treating Reclaimed Water (WRRF 10‐01). The Water Research Foundation (formerly the WateReuse Research Foundation): Denver, CO, 2014.
88
Figure 51 OPEX with this F/S (red line)25
Treatment cost of RO brine is estimated as follows. In this F/S, evaporator is supposed to be applied.
Table 40 Costs of RO concentrate management options for potable reuse treatment26
Treatment option Typical cost (USD/kgal) Applicability of this F/S
Deep well injection 0.21 ×
Brine line to ocean 0.35 ×
Land application, spray 0.35 △
Evaporation ponds 0.48 ○
Zero Liquid Discharge(ZLD) 2.38 To be investigated
25 Schimmoller, L; Kealy, M.J.: Fit for Purpose Water: The Cost of Over‐treating Reclaimed Water (WRRF 10‐01). The Water Research Foundation (formerly the WateReuse Research Foundation): Denver, CO, 2014. 26 EPA “2017 Potable Reuse Compendium” (2017)
89
4-3 Business model
The characteristics on technology of this F/S is to implement both physicochemical demineralizing
process utilizing RO membrane and separating process utilizing electrolysis, which is not just
combination of technologies but also contribution to gain recovery rate of RO membrane and to reduce
RO concentrate. Chemicals necessary for the treatment process are also produced on-site.
We can find innovative aspects in those technologies, hence taking intellectual properties by project
participants and partner companies is to be planned in the nexr step, in Japan or United States.
Table below shows the scenario of business model.
Table 41 Action in each business phase
Phase1
2019-
Basic study on technologies
Patent application
Public announcement
Phase 2
2020-
Showcase (demonstration project) by collaborating with US parners or end-
users
Phase 3
2021-
Demonstration project (continued)
Taking approvals or certifications
Making out proposals
90
5.Finance and economic evaluation
○ Economic Evaluation
CAPEX and OPEX of this F/S project is estimated as follows:
Table 42 CAPEX and OPEX
Basic conditions Capacity: 100 m3/h
TDS: 500 mg/L
CAPEX 4.6 million USD
OPEX 0.600 USD/m3 (2.639 million USD/MGD)
With conditions including above, pay-back years are estimated by setting combinations of conditions
of Na/Ca ratio of raw water (1.33 or 1.0), Separation by crystallizer (CR) (50% or 67%), TDS of raw
water (500 or 1,500) as in the table below:
Table 43 Pay-back years
Scenario Raw water Pay-back years Sensitivity
analysis
1 Na/Ca ratio =1.33
CR separation = 50%
TDS = 500 28.1 Figure 52
TDS = 1,500 12.5
2 Na/Ca ratio =1.33
CR separation = 67%
TDS = 500 13.8 Figure 53
TDS = 1,500 9.0
3 Na/Ca ratio =1
CR separation = 50%
TDS = 500 21.5 Figure 53
TDS = 1,500 10.8
Figure 52 PBY vs. TDS
(Scenario 1)
Figure 53 PBY vs. TDS
(Scenario 2)
Figure 54 PBY vs. TDS
(Scenario 3)
0
20
40
60
80
100
120
0 500 1000 1500 2000
Chemical PRICE300 ¥/kg400 ¥/kg500 y¥kg
回収期間(年)
TDS (mg/L)
0
5
10
15
20
25
30
35
40
45
50
0 500 1000 1500 2000
Chemical PRICE300 ¥/kg
400 ¥/kg500 y¥kg
回収期間(年)
TDS (mg/L)
0
10
20
30
40
50
60
70
0 500 1000 1500 2000
Chemical PRICE300 ¥/kg400 ¥/kg
500 y¥kg
回収期間(年)
TDS (mg/L)
91
UNR (University of Nevada, Reno) and NWII (Nevada Water Innovation Institute) have provided the
comments on the economics of this F/S as follows:
Capex is “competitive”.
Opex may be expensive. However, it may be inevitable in the condition of producing Class
A+ water, which is almost the same level with water quality required in DPR.
Sensitivity analysis for Capex and Opex is recommended.
10 years for pay back would be regarded economic.
Furthermote, there was the following comment:
In the existing IPR projects there is possibility of TDS increase in the aquifer, which is
thought to be due to the balance of water usage between winter and summer.
Hence we can suppose that TDS = 1,500 is within the probable range. In this canse, pay-back years
are estimated as 9.0 – 12.5 years, which are to be regarded economic.
○ Finance
In the economic evaluation shown above, simple estimate way of pay-back years is implemented,
without considerations of financing (Debt-Equity Ratio, loan rate, loan period, etc.).
Therefore, in the stage of phase 2 (showcase and demonstration project), it would be necessary to carry
out detailed economic evaluation taking financing conditions into consideration.
92
6.Governmental supports
◎ U.S. Federal Government
The Bureau of Reclamation has been supporting demonstration projects making use of adequate
technologies for various water-related problems.
The American West faces serious water challenges. Wide-spread drought, increased populations, aging
infrastructure, and environmental requirements all strain existing water and hydropower resources.
Adequate and safe water supplies are fundamental to the health, economy, and security of the country.
Through WaterSMART, Reclamation will continue to work cooperatively with states, tribes, and local
entities as they plan for and implement actions to increase water supply through investments to
modernize existing infrastructure and attention to local water conflicts.
The Bureau of Reclamation is making funding available through its WaterSMART Program for water
and energy efficiency grants. These grants will be awarded to projects that will result in quantifiable
and sustained water savings and support broader water reliability benefits.
About $24 million will be available through this funding opportunity. Funding is provided in two
groups. Funding Group I projects receive up to $300,000 and can be completed within two years.
Funding Group II projects may receive up to $1.5 million for a phased project up to three years.
Applicants must provide at least a 50 percent cost-share.
States, Tribes, irrigation districts, water districts and other organizations with water or power delivery
authority located in the western United States or United States Territories are eligible to apply for this
funding opportunity27.
Bureau of Reclamation also announced that Reclamation is awarding $35.3 million for six authorized
Title XVI water reclamation and reuse projects in California. The funding will be used to improve
flexibility during water shortages and diversify the water supply.
Table 44 Six projects in California awarded by the Bureau of Reclamation28
Applicant Project Award (USD)
City of Escondido Membrane Filtration Reverse Osmosis Facility
Project
5,000,000
City of San Diego Pure Water San Diego Program 9,000,000
City of San Jose South Bay Water Recycling Phase 1B
Infrastructure Improvements
2,545,471
27 https://www.usbr.gov/newsroom/newsrelease/detail.cfm?RecordID=64444 28 https://globalwatersecurity.org/content-hub/2019-02-08/Bureau-of-Reclamation-
awards-$353-million-to-six-water-reclamation-and-reuse-projects-in-California
93
Applicant Project Award (USD)
Elsinore Valley
Municipal Water District
Horsethief Canyon Wastewater Reclamation
Facility Expansion and Upgrade Project
2,693,455
Hi-Desert Water District Wastewater Treatment and Reclamation Project 8,668,500
Padre Dam Municipal
Water District
East County Advanced Water Purification Program 7,392,351
◎ State of California
State of California is managing and operating Water Recycling Funding Program (WRFP) and
providing supports for R&D and project implementation. Under that program, recycled water projects
are receiving a 1% financing commitment through the Clean Water State Revolving Fund (CWSRF)29.
WRFP also provides grants to assist public agencies with the construction of pilot projects for new
potable reuse. The applicant must demonstrate that the pilot project will develop new information that
does not currently exist and increase the body of knowledge regarding technologies that help the
understanding of how potable reuse can effectively be achieved through the innovative application of
current and new technologies. Eligible pilot projects may receive grant funds in the amount of up to
35% of actual eligible pilot study construction costs incurred up to a maximum of $1 million.
◎ State of Nevada
WaterStart, NPO under the Nevada Governor’s Office of Economic Development, are supporting
projects related to water, after gathering proposals from water technology companies to solve
immediate demands for innovation.
•Water quality pressure management in distribution systems
•Method for cleaning of water mains (trunk and reticulation) with limited impact on water quality
•Sediment formation reduction in drinking water networks
•Reducing the impact of surge/water hammer on the water network
•Early notification of contaminants entering reservoirs/tanks
•Prediction of trihalomethanes (THMs) concentration in drinking water supplies
•Improving field crew training in real-time (including virtual and/or augmented reality techs)
•Increasing water use efficiency in cooling towers
•Alternatives to conventional evaporative cooling
29 California Control Boards
https://www.waterboards.ca.gov/water_issues/programs/grants_loans/water_recycling/docs/1percent
_wrd_projects.pdf
94
•Alternatives for and/or reduction of chemical use in cooling towers and domestic supply lines (often
destructive to chillers and pumps)
•Treatment processes for improving water quality in swimming pools, saunas, and other water features
•Improving reliability and operation of drip irrigation systems
•Non-invasive monitoring systems to detect water leaks in electrical rooms
• Reduction of in-site disinfection byproduct formation for groundwater recharge applications
(TTHMs)30.
The table below shows the supporting programs by the federal and local governments.
Table 45 Supporting programs by the federal and local governments
Government Program Budget
USEPA Water Infrastructure
Finance Iinnovation Act
(WIFIA)
$20 million: Minimum project size for large
communities.
$5 million: Minimum project size for small
communities
(population of 25,000 or less).
USDA Rural
Utilities Service
Water & Waste Disposal
Loan & Grant Program
Loan/grant based on 50 percent of the State's
percentage of national rural population, 25
percent of the State's percentage of national rural
population with incomes below the poverty level
and 25 percent of the State's percentage of
national nonmetropolitan unemployment.
USDA Rural
Utilities Service
Individual Water and
Wastewater Grants
Maximum grant to any individual for WATER
service lines, connections, and/or construction of
a bathroom is $3,500.
Maximum grant to any individual for SEWER
service lines, connections, and/or construction of
a bathroom is $4,000.
Lifetime assistance to any individual for initial or
subsequent grants may not exceed a cumulative
total of $5,000.
Bureau of
Reclamation
Cooperative Watershed
Management Program:
Up to $100,000 per project over a two‐year
period.
30 WaterStart
https://waterstart.com/work-with-us/rfps/
95
Phase II Applicants must contribute at least 50% of the
total project costs.
Bureau of
Reclamation
Cooperative Watershed
Management Program:
Phase I
$50,000 per year for a period of up to two years
with no non‐Federal cost‐share required.
Bureau of
Reclamation
WaterSMART Drought
Response Program:
Drought Resiliency
Projects
Up to $300,000 per agreement for a project that
can be completed within two years or up to
$750,000 per agreement for a project that can be
completed within three years. Applicants must
provide a 50% non‐Federal cost‐share.
Bureau of
Reclamation
WaterSMART Drought
Response Program:
Drought Contingency
Planning
Varies
Bureau of
Reclamation
WaterSMART Grants:
Water and Energy
Efficiency Grants
Up to $300,000 for smaller projects or up to $1
million for larger projects. Applicants must
provide a 50% non‐Federal cost‐share.
Bureau of
Reclamation
Title XVI Water
Reclamation & Reuse
Program
In 2017, six projects received a total of
$20,980,129 for planning, design and/or
construction activities; 13 projects received a
total of $1,791,561 to develop new water
reclamation and reuse feasibility studies; and four
projects received a total of $847,701 for research
to establish or expand water reuse markets,
improve or expand existing water reuse facilities,
and streamline the implementation of clean water
technology at new facilities.
CoBank Rural Water and
Wastewater Lending
>$500,000
Bureau of
Reclamation
Water Purification
Research Program
Public/Private ‐ ‐ Public ‐ Private
Partnerships (P3)
‐‐Performance Based
Infastructure
Delivery & Service
96
Model
The Water
Research
Foundation
Private (subscribers) and
other funding
(state and federal)
Border
Environment
Cooperation
Commission
(BECC)
Technical Assistance
(TA) Fund
Varies
Border
Environment
Infrastructure
Fund (BEIF)
Border Environment
Infrastructure Fund
(BEIF)
Funding levels vary by annual congressional
appropriation; grant amounts are based on a
financial analysis of the project, utility and
community that takes into consideration eligible
projects costs and the availability of other
funding. BEIF grants cannot exceed $8 million.
North American
Development
Bank (NADB)
North American
Development Bank
(NADB) Loans
Any project, regardless of community size or
project cost, is eligible for financing and other
forms of assistance from NADB, if it meets all
three of the eligibility criteria. See
http://nadbank.org/programs/loans.asp#financing
for financing details.
North American
Development
Bank (NADB)
Community Assistance
Program (CAP)
Max $500,000. The project sponsor must
contribute at least 10% of the total project cost.
USEPA & Border
Environmental
Cooperation
Commission
(BECC)
Project Development
Assistance Program
(PDAP)
Varies
97
7.Estimate of CO2 emissions reduction and environmental impacts
Nevada uses several sources to generate electricity including natural gas, renewables, coal, and a small
amount from fuel oil or other gas. The combination of energy resources a utility uses to create
electricity is known as a resource mix, or portfolio. Currently, more than two-thirds of the State’s
electricity is produced by natural gas fired power plants; renewables comprise most of the remaining
amount; coal still remains as Nevada phases out its coal power plants.
Nevada has seen a significant increase in renewable energy production, and continues to develop its
abundant renewable energy resources such as geothermal and solar for use both within the State and
for exportation. Nevada has nearly doubled its renewable energy production during Governor
Sandoval’s administration beginning in 2011.
The Governor’s Office of Energy closely tracks the renewable energy generated in Nevada, whether
that energy is used in Nevada or exported to neighboring states. Renewable energy is defined in NRS
704.7811 as biomass, geothermal, solar, wind and waterpower. Waterpower is further defined as power
derived from standing, running or falling water which is used for any plant, facility, equipment or
system to generate electricity if the generating capacity is not more than 30 MWs.
Figure 55 Net Electricity Generation by Source in the State of Nevada (August 2017)31
In the charts below you will see Nevada’s renewable nameplate capacity, expressed in megawatts
(MW) and renewable electricity generation, expressed in megawatt-hours (MWh) numbers.
Awareness of the difference between nameplate capacity and electricity generation is critical to
improving reliability, lowering costs, and enhancing the integration of renewable resources.
Nameplate capacity is the maximum rated electric output a generator can produce under specific
conditions, and generation is the amount of electricity a generator produces over a specific period of
31 State of Nevada Governor’s Office of Energy “2017 Status of Energy Report”
98
time. The difference is due to the fact that many generators do not or cannot operate at their full
nameplate capacity all the time.
Figure 56 Renewable Power in the State of Nevada (Left: Capacity, Right: Generation) (2016)32
Energy consumption is the amount of energy used in a process, organization, or society. The chart
below on the left shows the breakdown of energy consumption in Nevada by percentage. About 88%
of the fuel for energy in Nevada consumes comes from outside the State.
Figure 57 Energy Consumption (Left) and Expenditures (Right) in the State of Nevada (2015)33
32 State of Nevada Governor’s Office of Energy “2017 Status of Energy Report” 33 State of Nevada Governor’s Office of Energy “2017 Status of Energy Report”
99
The table below shows the programs relating to this F/S project. Currently there is no financial support
program, however, there is a possibility that those programs are changed after June 2019, based on the
new policy by the new governer Steve Sisolak. 34
Table 46 Energy-related programs in the State of Nevada35
AB5 / Property Assessed
Clean Energy (PACE)
Financing mechanism that enables low-cost, long-term funding for
energy efficiency and renewable energy projects.
Revolving Loans for
Energy Efficiency and
Renewable Energy (NRS
701.545)
Funded from the American Recovery and Reinvestment Act (ARRA)
of 2009, the fund provides short term low-cost loans to developers of
eligible projects in Nevada. These loans serve as a bridge financing
option for various costs associated with these projects. Eligible
applicants may receive a minimum of $100,000 and a maximum of $1
million. Loan terms are up to 15 years with an interest rate of 3% or
less.
RPS (Renewable
Portfolio Standard)
Nevada’s Renewable Portfolio Standard (RPS), NRS 704.7801, was
adopted by the Nevada Legislature in 1997. The RPS establishes the
percentage of electricity sold by an electric utility to retail customers
that must come from renewable sources.
Specifically, electric utilities are required to generate, acquire, or save
with portfolio energy systems or energy efficiency measures, a certain
percentage of electricity annually.
AB223/SB150 AB223/SB150 requires that NV Energy’s overall energy efficiency
plan be cost effective, not necessarily every single program or
component that is included in the plan. AB223/SB150 requires that at
least 5% of the total budget for energy efficiency programs be directed
to programs targeting low-income households. These households need
energy efficiency assistance the most.
Performance Contact
Audit Assistance Program
(PCAAP)
Program to assist energy audit.
Reduction of energy consumption by implementing the F/S project is to be estimated as follows:
34 NWIC (August 2018) 35 NWIC (August 2018)
100
Table 47 Scenarios to estimate energy reduction
Scenario Water treatment method (1) Brine treatment
(2) Procurement of
chemicals
Reference Conventional RO Evaporator (①) + Landfill
(②)
Purchase HCl, NaClO
and NaOH from out of
the project boundary
(③)
Project Zero Liquid Discharge
(ZLD)
Evaporator (①) + Landfill
( ② ) (Treated amount is
smaller than reference)
Zero (③’)
The difference of the brine emission is as follows, in the condition of TDS 500 and flow rate
1,000m3/H:
Table 48 Brine emissions
Scenario Recovery rate Brine emissions
Reference 75% 250 m3/H
Project 98% 20 m3/H
(1) Evaporator
Electricity consumption for 1m3 in the evaporator:
72kWh × 24H × 80% ÷ (2m3/H × 24H) =28.8kWh/m3
(1kWh=3.6MJ)
○ Conventional RO
Electricity consumption in a day:
28.8kWh/m3 × 250m3/H × 24H = 172,800kWh/day
172,800kWh/day × 3.2 MJ/kWh = 552,960MJ/日 ・・・①
○ ZLD
Electricity consumption in a day:
28.8kWh/m3 × 20m3/H × 24H = 13,820kWh/day
13,820kWh/日 × 3.2MJ/kWh = 44,236 MJ/日 ・・・①'
101
Reduction of CO2 emission is estimated by using CO2 emission efficiency in the State of Nevada 0.37
t-CO2/MWh:
(172,800 – 13,820) kWh/day ÷ 1,000 × 0.37 t-CO2/MWh
= 58.8 t-CO2/day
Reduction ①-①' = 508,724 MJ/day and 58.8 t-CO2/day
(2) Landfill
Distance from the plant to the landifill site: 200km;
Disposal amount: 10m3;
Fuel consumption: 10km/L (diesel fuel);
Calorie of diesel fuel: 1L=38.2MJ/L
○ Conventional RO:
Amount of brine:
(250m3/H × 24H) ÷ 30 (concentrate) = 200m3/day
Times of disposal:
200m3/day ÷ 10m3 = 20 times/day
Distance of disposal:
20 times/day × 200km × 2 = 8000km/day
Consumption of fuel:
8000km/day ÷ 10km/L = 800L/day
800L/日 × 38.2 MJ/L =30,560MJ/日 ・・・②
○ ZLD
Amount of brine:
(20m3/H × 24H) ÷ 30 (concentrate) = 16m3/day
Times of disposal:
16m3/day ÷ 10m3 = 1.6 times/day
Distance of disposal:
1.6 times/day × 200km × 2 = 640km/day
Consumption of fuel:
640km/day ÷ 10km/L = 64L/day
102
64L/day × 38.2 MJ/L =2445MJ/day ・・・②'
Reduction of CO2 emission is estimated by using CO2 emission efficiency of the diesel fuel 0.0686
tCO2/GJ:
(30,560 – 2,445) MJ/day ÷ 1,000 × 0.0686 t-CO2/GJ
= 1.93 t-CO2/day
Reduction ②-②' = 28,115 MJ/day and 1.93 t-CO2/day
(3) Procurement of chemicals
Distance from the plant to the landifill site: 200km;
Fuel consumption: 10km/L (diesel fuel);
Calorie of diesel fuel: 1L=38.2MJ/L
○ Conventional RO
HCL
HCL consumption:
18m3/ H × 338mg/L = 6.084kg/H
6.084kg/H × 24H = 146kg/day
146kg/日 ÷ 35% =417kg/day ・・・ⓐ
35% = 350,000 mg/L =350kg/m3 ・・・ⓑ
ⓑ ×10m3/time ÷ ⓐ = 8.39day/time ・・・©
Diesel fuel consumption:
200km × 2 = 400km/time
400km/time ÷ 10km/L = 40L/time
40L/time ÷ 8.39 day/time = 4.77L/day
4.77L/day × 38.2 MJ/L =182MJ/day ・・・Ⓐ
NaOH
NaOH consumption:
9m3/ H × 924mg/L = 8.316kg/H
8.316kg/H × 24H = 200kg/day
200kg/day ÷ 24% =833kg/day ・・・ⓐ'
25% = 250,000 mg/L =250kg/m3 ・・・ⓑ'
103
ⓑ' ×10m3/time÷ ⓐ' = 3.00 day/time ・・・© '
Diesel fuel consumption:
200km × 2 = 400km/time
400km/time ÷ 10km/L = 40L/time
40L/time ÷ 3.00 day/time = 13.33L/day
13.33L/day × 38.2 MJ/L =509MJ/day ・・・Ⓑ
Ⓐ+Ⓑ=691MJ/day ・・・③
○ ZLD
0 MJ/day ・・・③'
Reduction of CO2 emission is estimated by using CO2 emission efficiency of the diesel fuel 0.0686
tCO2/GJ:
(691 – 0) MJ/day ÷ 1,000 × 0.0686 t-CO2/GJ
= 0.0474 t-CO2/day
Reduction ③-③' = 691 MJ/day and 0.0474 t-CO2/day
Table 49 Reduction of energy consumption and CO2 emission
Reduction of energy consumption Reduction of CO2 emission
(1) Evaporator 508,724 MJ/day 58.8 t-CO2/day
(2) Landfill 28,115 MJ/day 1.93 t-CO2/day
(3) Chemicals 691 MJ/day 0.0474 t-CO2/day
Total 537,530 MJ/day
60.8 t-CO2/day
22,200 t-CO2/year
104
8.Risk analysis
The general framework of risk analysis is shown in the table below.
The risk analysis itself is to be conducted after identifying and deciding important project components
including financial plan.
Table 50 Framework of risk analysis
Political risks Commercial risks Macro-economic risks
Change of law risks
Quasi-political risks
Investment risks
Commercial viability
Completion risks
Environmental risks
Operating risks
Revenue risks
Input supply risks
Force majeure risks
Inflation
Interest rate risks
Exchange rate risks
On the political risks, the risk against change of guidelines or regulations on IPR projects is to be
focused, including LRV or applied category (A+) for the treated water.
On the commercial risks, so as to minimize them, the followings are to be implemented in the next
phase:
CAPEX estimate based on the detailed data and project conditions;
OPEX estimate based on the detailed data and project conditions;
Identification and selection of project participants;
Financial plan based on the project participants’ and financer’s interests or decisions;
Cash-flow analysis based on CAPEX, OPEX and financial plan; and
Conditions and procedures of applying the advanced technologies (phase 2).
On the macro-economic risks, general risks are to be investigated.
105
9.Project potential in the United States and the strategy
The State of California has a plan to start DPR operation until the end of 2023, which means there will
be requirements to decrease RO brine from 2020 to 2025.
The figure below shows the market outlook of water reclamation in the important 5 states.
Figure 58 Market outlook of water reclamation in the important 5 states 36
Carollo’s case study evaluation of how the technologies could be implemented in the five states is
described below. Participation in this project by these utilities is for illustration only, and does not
represent an endorsement of the technology by any of these utilities or cities.
36 BlueField Research
106
Figure 59 Cities which have probabilities
Table 51 Cities which have probabilities
City Characteristics and background
Nevada - Reno (Target of the
F/S)
Technology evaluation has been carried out manly by UNR
(University of Nevada, Reno) and NWII (Nevada Water
Innovation Institute). There is requirement of minimizing RO
concentrate emission and procurement of chemicals because of
inland area.
Florida - City of Altamonte
Springs
The City of Altamonte Springs operated a GAC-based potable
water reuse pilot facility in 2016/2017 (pureALTA). The
treatment processes included ozone, biologically active filtration,
ultrafiltration, and granular activated carbon filtration. These
processes were selected over an RO-based treatment approach
due to concerns about the cost of implementing RO, particularly
for RO concentrate disposal.
Altamonte Springs is north of Orlando, situated more than 50
miles from the Atlantic coast of Florida. Although Florida is a
peninsula, the distance for central communities make the cost of
constructing an ocean outfall cost prohibitive unless a regional
interceptor approach was developed for multiple utilities. For this
project, the evaluation of implementing an RO-based potable
Surprise - Arizona
El Paso - Texas
Altamonte Springs - Florida
Clovis - California
Reno- Nevada
107
City Characteristics and background
water reuse treatment process would rely on either evaporation
ponds, deep well injection, or zero liquid discharge for disposal
of the concentrate.
California - City of Clovis The City of Clovis is located near Fresno, approximately 100
miles inland from the Pacific Ocean. The City has operated a Title
22 reuse facility for nonpotable water uses since 2010. Potable
water reuse has been considered as a future water source for their
system. Similar to the other case study locations, the location and
climate for this facility is conducive to evaporation ponds for RO
concentrate disposal.
Texas - El Paso Water Utilities The El Paso Water Utilities operated a RO-based pilot in 2015.
The pilot included pre-ozone, MF/UF, RO/NF, UV/AOP, and
GAC. The full-scale facility is currently in the preliminary design
phase (by Carollo). Similar to Altamonte Springs, the location
and climate for this facility is conducive to evaporation ponds for
RO concentrate disposal.
Arizona - City of Surprise The City of Surprise is located northwest of Phoenix and has
operated a recycled water system that produces A+ water for
agricultural irrigation, groundwater recharge, landscape
irrigation, and dust control. Similar to the other case study
locations, the location and climate for this facility is conducive to
evaporation ponds for RO concentrate disposal.
108
10.Technological superiority of Japanese companies and estimate of profit for
Japanese participants
10-1 Comparison of technologies between Ozone-BAC and RO
As mentioned above, in the South Truckee Meadows Water Reclamation Facility at the City of Reno,
the demonstration project has been implemented by applying Ozone-BAC treatment technology. NWII,
the project manager, compares the characteristics between conventional RO and Ozone-BAC methods:
Table 52 Comparison of technologies between Ozone-BAC and RO37
In the stage of investigating and comparing the applied technologies for future IPR project including
demonstration by NWII, the major premise is pathogens of the treated water meets the standard of
Caltegory A+ and the other water quality data is acceptable.
NWII indicates that TDS may be equal or worse than the raw water in the aquifer. On the other hand,
this F/S shows the pay-back period will become better in accordance with TDS.
Therefore, we can result that our technology advantage may be high under the situation of closed
environmental buffer.
10-2 Cost comparison between the conventional RO and the F/S
The table below shows the cost comparison between conventional RO and advanced RO (This F/S) in
the candidate sites. CAPEXs in the projects in which F/S technology is applied are bigger than
conventional by 2.7 – 5.7 times, however, it is probable the F/S project is accepted where high recovery
37 Vijay Sundaram PE, Lin Li, Tatiana Guarin, Lydia Peri PE, Rick Warner PE and Krishna Pagilla
PhD, PE “Overcoming Challenges in Ozone-Biofiltation Treatment Systems for IPR Applications”
(2019/1/30)
109
and brine minimization are required.
Table 53 Cost comparison between conventional RO and the F/S
City Typical Disposal cost of the
conventional RO treatment
(USD/day)
Disposal cost of the
proposed ZLD/ZCC RO
treatment (USD/day)
Ratio
Nevada - Reno (Target of the
F/S)
Ozone + BAC -
Florida - City of Altamonte
Springs
1,500 4,240 2.8
California - City of Clovis 240 749 3.1
Texas - El Paso Water Utilities 1,284 7,252 5.7
Arizona - City of Surprise 569 3,873 4.3
10-3 Identification of the Japansese portion
Technological superiority of each project element equipment is as follows:
Table 54 Technological superiority of each project element
Process Superiority of Japanese technology Japanese portion
RO1st (low-pressure) High recovery rate by 75% Toray product
Crystallizer Drastic reduction of scaling components followed
by supplying to RO2nd, RO3rd and ELS1
Procurement from
foreign companies
ELS1 Concentration of specific ions Japanese
technology
ELS2 Production of chemicals used in the F/S process
which contribute to reduce waste
Japanese
technology
RO2nd
(middle-pressure)
Stable operation under the condition of wide-
randged pH
Toray product
110
RO3rd
(high-pressure)
Total recovery rate by more than 98% Toray product
10-4 Profit for Japanese participants
The investment outlook of the water treatment in the State of California which is supposed to be one
of the largest market in the United States is shown in the table below:
Table 55 Investment outlook of IPR/DPR in California38
Year Investment
(million USD)
2023 350
2024 380
2025 606
Profit for Japanese participants in the future projects in the western part of United States is to be
estimated as follows:
Trend of investment is similar in the 5 states studied in this F/S with California.
Percentage of Japanese portion in the investment = 90%
Target of the market share of IPR/DPR = 10%
Profit for Japanese participants =
39, 161 and 164 million USD in the year 2023, 2024 and 2025, respectively.
38 BlueField Research
111
11.Report Meeting
The final report meeting was held in the University of Nevada, Reno and NWII on January 31st, 2019.
Date January 31st 2019 8:30~12:30
Place University of Nevada, Reno
Table 56 Summary of discussions
Project details In the existing IPR projects there is possibility of TDS increase in
the aquifer, which is thought to be due to the balance of water
usage between winter and summer.
There is interest to make sodium hypochlorite as the bi-product.
Profitability Capex is “competitive”.
Opex may be expensive. However, it may be inevitable in the
condition of producing Class A+ water, which is almost the same level
with water quality required in DPR.
Sensitivity analysis for Capex and Opex is recommended.
10 years for pay back would be regarded economic.
Futute collaborations Shared understanding on the F/S results.
It should be investigated whether pilot testings are implemented
only in Japan or both in UNR and Japan.
Plant tank should be within the size of container.